A note of clarification - As you read and study 2Corinthians 3, especially the passages in which Paul contrasts the Old Covenant with the New Covenant, you must understand that the New Covenant is the heart of the Gospel and is based solely on grace not law. To preach the Gospel is in essence to preach the New Covenant. It therefore behooves us to understand the glorious good news of the New Covenant, so that we can experience the life and freedom that it offers and avoid the subtle trap of succumbing to various forms of legalism which in one way or another are simply permutations of the Old Covenant of Law and which invariably produce a stagnant, frustrating, "dead" Christian experience accompanied by a sense of condemnation rather than a realization of true freedom that is found in Christ, our New Covenant Messenger (Malachi 3:1) Who "cut the New Covenant" in His body and blood on the Cross (Lk 22:20, 1Co 11:24, 25). As an aside, remember that Old Testament saints were saved by grace through faith and not by keeping the Law, which is an all too common misconception even among evangelical believers! Clearly those individuals do not understand 2 Corinthians 3 in which Paul describes the Old Covenant as a ministry of death and a ministry of condemnation!

You are probably thinking something like "This section of Scripture doesn't strike me as that significant." Let me encourage you that to the contrary, this section of Scripture is an integral component of the riches Paul under the inspiration of the Spirit has laid away for us to discover. May the excellent devotional writer J C Philpot's comments encourage you to do more than just quickly read through this great chapter...

We know no part of Scripture where the law and the gospel are more clearly, concisely, and beautifully contrasted than in that remarkable chapter, 2 Corinthians 3. The whole chapter demands and will amply repay the most careful and prayerful examination and meditation; for in it the Apostle places in striking contrast the two dispensations—the main points of contrast being the peculiar glory of each covenant, but the surpassing glory of the New Covenant. Paul does not, like some uninspired teachers, disparage the Law, or push it contemptuously out of the way, but gives it due honor as a revelation from God, and as such, therefore, possessing a glory of its own. Following his invariable method of basing all his assertions on Scripture, he founds his view of the peculiar glory of the old dispensation upon a remarkable occurrence at the time of its revelation— (2Cor. 3:7.)...In the midst of this glory Moses was, as it were, wrapped up; for he was the typical mediator of that covenant. When, then, he came down from the mount a second time with the two tables in his hands, the skin of his face shone, as if the glory of God in that covenant were reflected in it. The shining of his face Paul calls "the glory of his countenance," that being the reflection of the glory of God as seen by him face to face during the forty days' sojourn. (The Precepts of the Word of God)

C H Spurgeon wrote that...

Christ has made for us a New Covenant. The Old Covenant was,

Do this and live

That covenant was a sentence of death upon us all. We could not do, therefore we could not live, and so we died. The New Covenant has nothing in it contingent upon creature doing, but it bases all its provisions upon Christ having done the world.

I will, and you shall

This is the language of the new covenant. The Covenant of Law, in which we were weak through the flesh, left us mangled and broken. The Covenant of Grace reveals God's kindness towards us, and our part thereof has been fulfilled for us by our surety, Christ Jesus. Thus it runs,

Their sins and their iniquities will I remember no more for ever; a new heart also will I give them, and a right spirit will I put within them.

The old world (Ed: All who have not entered into the New Covenant) is still under the Old Covenant of works, and its children perish, for they cannot carry out the conditions of the covenant, they cannot keep God's law, they break it constantly, and they die. But the children of grace are under the New Covenant of grace, and through the precious blood, which is the penalty of the old broken covenant, and through the spotless righteousness of Christ, which is the fulfilment and magnifying of the Old Covenant, the Christian stands secure, and rejoices that he is saved. Christ has thus made His people dwell under a New Covenant, instead of under the old one. (Ed: This begs the question - Under which covenant are you living your Christian life? Be introspective. Be honest! Be free!) (Spurgeon's entire sermon - A New Creation)

More of C H Spurgeon on the New Covenant...

WHAT a glorious covenant the second covenant (New Covenant) is! Well might it be called a better covenant, which was established upon better promises.” Hebrews 8:6.

It is so glorious that the very thought of it is enough to overwhelm the soul, when it discerns the amazing condescension and infinite love of God, in having framed a covenant for such unworthy creatures, for such glorious purposes, with such disinterested motives.

It is better than the other covenant, the "covenant of works", which was made with Adam; or that covenant which is said to have been made with Israel, on the day when they came out of Egypt. It is better, for it is founded upon a better principle. The Old Covenant was founded on the principle of merit; it was

Serve God and you shall be rewarded for it. If you walk perfectly in the fear of the Lord, God will walk well towards you, and all the blessings of Mount Gerizim shall come upon thee, and you shall be exceedingly blessed in this world, and the world which is to come.

But that covenant fell to the ground, because, although it was just that man should be rewarded for his good works, or punished for his evil ones, yet man being sure to sin, and since the fall infallibly tending towards iniquity, the covenant was not suitable for his happiness, nor could it promote his eternal welfare.

But the New Covenant, is not founded on works at all, it is a covenant of pure unmingled grace; you may read it from its first word to its last, and there is not a solitary syllable as to anything to be done by us....(the) New Covenant has now nothing whatever to do with the creature, so far as the creature has to do anything, but only so far as he is to receive: the idea of change is utterly and entirely gone. It is God’s Covenant, and therefore it is an unchanging covenant. If there be something which I am to do in the covenant, then is the covenant insecure. And although happy as Adam, I may yet become miserable as Satan. But if the covenant be all on God’s part, then if my name be in that covenant, my soul is as secure as if I were now walking the golden streets. And if any blessing be in the covenant, I am as certain to receive that blessing as if I already grasped it in my hands; for the promise of God is sure to be followed by fulfillment. The promise never fails. It always brings with it the whole of that which it is intended to convey, and the moment I receive it by faith, I am sure of the blessing itself. Oh! how infinitely superior is this Covenant to the other in its manifest security! It is beyond the risk or hazard of the least uncertainty.

But I have been thinking for the last two or three days, that the Covenant of Grace excels the other covenant most marvellously in the mighty blessings which it confers.

What does the covenant of grace convey?

I had thought this morning of preaching a sermon upon “The covenant of grace; what are the blessings it gives to God’s children?” But when I began to think of it, there was so much in the covenant, that if I had only read a catalogue of the great and glorious blessings, wrapped up within its folds, I should have needed to occupy nearly the whole of the day in making a few simple observations upon each of them. Consider the great things God has given in the covenant. He sums them up by saying he hath given

ALL THINGS!

He has given you eternal life in Christ Jesus; yea, he has given Christ Jesus to be yours; He has made Christ heir of all things, and He has made you join their with Him; and hence He has given you everything. Were I to sum up that mighty mass of unutterable treasure which God has conveyed to every elect soul by that glorious covenant, time would fail me. I therefore commence with one great blessing conveyed to us by the covenant, and then on other Sabbaths I will, by Divine permission, consider separately, one by one, sundry other things which the covenant conveys.

We commence then by the first thing, which is enough to startle us by its immense value; in fact, unless it had been written in God’s Word, we never could have dreamed that such a blessing could have been ours. God himself, by the covenant becomes the believer’s own portion and inheritance. 

I WILL BE THEIR GOD!

...Stop just one moment and think it over before we start. In the Covenant of Grace God Himself conveys Himself to you and becomes yours. Understand it: God — all that is meant by that word — eternity, infinity, omnipotence, omniscience, perfect justice, infallible rectitude, immutable love — all that is meant by God — Creator, Guardian, Preserver, Governor, Judge, — all that that great word “GOD” can mean all of goodness and of love, all of bounty and of grace — all that, this covenant gives you, to be your absolute property as much as anything you can call your own: “I will be their God.” We say, pause over that thought. If I should not preach at all, there is enough in that, if opened up and applied by the all-glorious Spirit, to excite your joy during the whole of the Sabbath-day. “I will be their God.”(Excerpt from God in the Covenant = based on Jer 31:33 "I will be their God.")

Thomas Brooks...

The covenant of grace (New Covenant) is the saint's original title to heaven...The whole covenant is a bundle of promises.

See these related resources:

John MacArthur comments that...

2Cor 3:6-18 is almost like a reduced version of the book of Hebrews. It takes the book of Hebrews, the great concept of the superiority of the New Covenant, and reduces it to this one little section of passages. (The Glory of the New Covenant, Part 4)

John MacArthur makes the point that in 2Corinthians 3 Paul teaches truths that will help his readers...

understand the transition from the Old covenant to the New.

It isn't that the Old Covenant and New Covenant are opposites.
It isn't that they are opposed to each other.
It is that one gives way to the next.

The Old Covenant in and of itself was not complete, it could not save, it could not grant righteousness. It had to pass away and be replaced by the New. The Old Covenant, however, did serve a purpose, a very good purpose and that purpose was fulfilled historically (Ed: See Why the Law?). And when the time came for that purpose to fade, it faded and the New Covenant came in its place. (The Glory of the New Covenant, Part 3 - this sermon also includes an interesting discussion on what Dr MacArthur refers to as the three "categories" of Old Covenant Law - civil, moral and ceremonial.)

The UBS Handbook notes that...

In 2Cor 3:7-11 Paul uses a form of argument used by the rabbis of his day: from the lesser to the greater. If such and such could be said concerning something relatively unimportant (the lesser), then how much more could such and such be said concerning the greater, or more important matter. The comparison in these verses is between the Law of Moses (the lesser) and the new covenant (the greater). Verses 7 and 8 are one long and rather complicated sentence in Greek...Paul’s argument in these verses is based on the story in Ex 34.27–35 of Moses’ encounter with God on Mount Sinai. (The United Bible Societies' New Testament Handbook Series or Logos)

But if - Paul now develops the contrast he introduced in 2Co 3:7 and in a sense even alluded to in 2Co 3:3 comparing the external writing on stone (Old Covenant) versus the Spirit's writing on the hearts of the saints at Corinth (New Covenant).

Here are the 3 sets of "which utilize the rabbinical exegetical middah of 'the light and the heavy'" (R. Martin)...

But if (2Co 3:7)...even more (2Co 3:8)
For if (2Co 3:9)...much more (2Co 3:9)
For if (2Co 3:11)...much more (2Co 3:11)

Expositor's Bible Commentary writes that Paul's allusion to the NT...

now prompts him to compare the old and new economies. Each involved a distinctive ministry that was accompanied by glory, but so superior was the glory of the new covenant that the glory of the old faded into insignificance by comparison...in the remainder of the chapter Paul provides a commentary on selected points of the narrative in Exodus 34:29–35.  (Gaebelein, F, Editor: Expositor's Bible Commentary 6-Volume New Testament. Zondervan Publishing or computer version)

Ministry of death - The Greek is subjective genitive meaning "marked by death in its outcome" (A T Robertson) and was a graphic description of the ministry of Moses (and the Old Covenant of Law), because as Paul had just stated, the letter kills (2Co 3:6-see explanation of why the letter killed).

THE GREATEST MASS
MURDERER OF ALL TIME!

MacArthur explains ministry of death bluntly stating that the...

Law is a killer. Are you ready for this? Law is the greatest "mass murderer" in the world's history. That's right. Law is a killer beyond all killers. It has a ministry of death. The Law of God has a ministry of death. It slays everyone who gets in front of it.

Let me illustrate that by having you go to Romans 7:7-note,

"What shall we say then, is the Law sin? Well the answer, may it never be,"...

The Law is not sin, nothing wrong with the Law, it's holy, just and good. The Law is not sin. "But, on the contrary," look at Ro 7:7-note , this is so powerful,

"I would not have come to know sin except through the Law."

Now how would I know I was sinning if there was not a Law to define my sin? And he gives an illustration.

"I would not have known about coveting if the Law had not say, `You shall not covet.'"

I wouldn't have known that. "Now if there's no Law then there's no way to define sin." So Paul says,

"The Law came to define sin, apart from the Law I wouldn't know I was a sinner."

If He don't tell me coveting is a sin, I'm not going to know that it's wrong to do that. So the Law came...notice this now...the Law came to define sin...Paul says I was fine until I ran into the Law. And when I ran into the Law, I said...covet? Covet? You can't do that? I just thought that was just normal human behavior...covet, covet, covet, covet. I just...I coveted almost everything I saw....It's just the way that the Law is made that when it confronts the fallenness of man it defines his sin and it exacerbates his sin...  the end of Ro 7:8-note he says,

"Apart from the Law sin is dead. And I was once alive apart from the Law but when the commandment came, sin became alive and I died."

What do you mean? Well he died a spiritual death. He realized that his condition was spiritual death. He realized he was cut off from the life of God, that he was a sinner, he was doomed. The commandment which God intended to result in life was death to me...death to me. The end of Ro 7:11-note, "It killed me." So then the Law is holy and the commandment is holy, and righteous and good. The problem is not with the Law, the problem is...what?...with me...with me. (The Glory of the New Covenant, Part 3)

Guzik asks...

Was it wrong to call the old covenant the ministry of death? No, because that is what the law does to us: it slays us as guilty sinners before God, so we can be resurrected by the new covenant. Not that the problem was with the law, but with us: the sinful passions which were aroused by the law were at work in our members to bear fruit to death. (Romans 7:5-note)

John Trapp has an interesting comment on ministry of death writing that...

David was the voice of the law awarding death to sin, ‘He shall surely die.’ Nathan was the voice of the gospel awarding life to repentance for sin, ‘Thou shalt not die.’”

Vincent comments that ministry of death...

is that of Moses, and does not apply to his entire career as Israel’s lawgiver, but to his particular ministry in receiving on Sinai and transmitting to the people the law of God. The ministration may be said to have been graven on stones, since the whole purport of that economy which he represented was contained in the tables, and he was its minister in being the agent through whom God delivered it to the people.

Ministry (1248)(diakonia) means the rendering or assistance or help by performing certain duties, often of a humble or menial nature serve, including such  mundane activities as waiting on tables or caring for household needs. In this section of Corinthians, diakonia, is used somewhat figuratively to speak of the service rendered by the two covenants Paul is contrasting.

Paul had just explained that the Old Covenant of the Law "kills" (2Co 3:6) for as Romans 7:10

and this commandment, which was to result in life, proved to result in death for me;

Letters engraved on stones (2Co 3:3) - Literally "engraved on stones by means of letters"

The Tablets God wrote on Mt Sinai...

Now the Lord said to Moses, “Come up to Me on the mountain and remain there, and I will give you the stone tablets with the law and the commandment which I have written for their instruction.” (Exodus 24:12)

When He had finished speaking with him upon Mount Sinai, He gave Moses the two tablets of the testimony, tablets of stone, written by the finger of God. (Ex 31:18, cp 32:15,16,19 34:1,28 Dt 4:13 5:22 9:9-11,15 Dt 10:1-4 Heb 9:4)

Engraved (1795) (entupoo from en = in + tupos = form, stamp) means to stamp in or on and so to engrave. Used only here in Scripture describing the forming of letters by carving or incising in this case on stones.

Stones (plural) (3037) (lithos) a piece of rock, a a concretion of earthy or mineral matter of indeterminate size or shape. Stones are of various degrees of hardness and weight; they are brittle and fusible, but not malleable, ductile, or soluble in water. Lithos is used figuratively to refer to Christ as "the stone which the builders (Israel) rejected", the chief corner stone of the God's spiritual temple. Peter uses lithos figuratively to describe believers as living stones "who are being built up as a spiritual house" (1Pe 2:5-note). Here Paul is clearly referring to the two stone "tablets of the testimony, tablets of stone, written by the finger of God." (Ex 31:18).

The first tablets of stone which Moses broke in anger were engraved by God as recorded in Exodus 32...

Then Moses turned and went down from the mountain with the two tablets of the testimony in his hand, tablets which were written on both sides; they were written on one side and the other. The tablets were God’s work, and the writing was God’s writing engraved on the tablets.  (Ex 32:15, 16).

Comment: The Stones or Tablets refer to what we commonly call "The Ten Commandments" (the "Ten Words") - These were a summary of the moral law reduced to ten commandments, which summarized the whole law, even as the essence of the ten commandments is summarized in the two commands to "Love the Lord your God with all your heart, and with all your soul, and with all your mind and with all your strength...(and) love your neighbor as yourself." (Mk 12:30, 31).

THE GLORY ON THE
FACE OF MOSES

The second set of two tablets of the "Ten Commandments" were written not by the finger of God but by Moses...

Then the LORD said to Moses, "Write down these words, for in accordance with these words I have made a covenant with you and with Israel." So he was there with the Lord forty days and forty nights; he did not eat bread or drink water. And he wrote on the tablets the words of the covenant, the Ten Commandments. And it came about when Moses was coming down from Mount Sinai (and the two tablets of the testimony were in Moses' hand as he was coming down from the mountain), that Moses did not know that the skin of his face shone because of his speaking with Him. 30 So when Aaron and all the sons of Israel saw Moses, behold, the skin of his face shone, and they were afraid to come near him. 31 Then Moses called to them, and Aaron and all the rulers in the congregation returned to him; and Moses spoke to them. 32 And afterward all the sons of Israel came near, and he commanded them to do everything that the LORD had spoken to him on Mount Sinai. 33 When Moses had finished speaking with them, he put a veil over his face. (2Co 3:13) 34 But whenever Moses went in before the LORD to speak with Him, he would take off the veil until he came out; and whenever he came out and spoke to the sons of Israel what he had been commanded, 35 the sons of Israel would see the face of Moses, that the skin of Moses' face shone. So Moses would replace the veil over his face until he went in to speak with Him.  (Ex 34:27, 28, 29, 30, 31, 32, 33, 34, 35).

Came with glory - was made glorious (literally "in glory"). The Old Covenant (Law) had a degree of supernatural glory, brightness and splendor which Paul explains below was evident on the face of Moses (not on the tablets per se), not to mention the glory on the mountain manifest by "lightning flashes and a thick cloud upon the mountain and a very loud trumpet sound...in smoke because the LORD descended upon it in fire; and its smoke ascended like the smoke of a furnace, and the whole mountain quaked violently, so that all the people who were in the camp trembled." (Ex 19:16, 18) Paul did not despise the Law of God as his enemies suggested, for "It came with glory" and "is holy and the commandment is holy and righteous and good." (Ro 7:12) What Paul did despise was the misuse of the Law by the false teachers. So Paul does not argue that the Old Covenant lacked glory but clearly states it had glory. But as he goes on to add, this glory was a fading glory, a temporary glory, a glory that was now replaced by the glory of the New Covenant which in place of death and condemnation brings life and righteousness. And so in this section we are studying, Paul illustrates the fading glory of the Old Covenant by referring to the time when Moses encountered God and had his face transformed so that it reflected God's glory. Even as the glory on Moses' face faded, so too the glory of the Old Covenant had "faded" away and was now replaced by the permanent glory of the New Covenant.

Glory (1391)(doxa) which in this context describes splendor or that which emanates great brightness or luster, brilliance, effulgence, radiance, resplendence. Doxa is a key word in this chapter where it is used 11x - three times in 2Co 3:18, twice in 2Co 3:7, 3:9, 3:11, once in 2Co 3:8, 10.

Vincent comments that the KJV's translation of was glorious is...

A very inadequate translation. Egenethe means came to pass or took place, not simply was. A glory passed from God to Moses, so that his face became shining. It is much more graphic and truthful to render en doxe literally, in or with glory, than to convert the two words into a single adjective, glorious. Rev., much better, came with glory.

Guzik...

There was a glory associated with the giving of the law and the old covenant. At that time, Mount Sinai was surrounded with smoke, there were earthquakes, thunder, lightning, a trumpet blast from heaven, and the voice of God Himself (Exodus 19:16-20:1). Most of all, the glory of the old covenant was shown in the face of Moses and the glory of his countenance.

Ray Stedman...

He says there is a kind of glory about the old covenant, there is an attractiveness about it, symbolized here by the brightness of Moses' face when he came down from the mountaintop with the tables of the Law. God made his face to shine, not Moses; and it was grace, not grease. But God also made it fade, because he wanted to teach something by that. It was a fading glory (Have you got What it Takes 2 Corinthians 3:1-11)

Matthew Poole contrasts the coming of the glory of the Law with that of the Gospel writing that...

the Gospel did not come into the world as the Law did with thunder, lightning, and earthquakes, but was ushered in by angels (Ed: with the "glory of the Lord" Lk 2:9), foretelling the birth and office of John the Baptist, and of Christ; by the great sign of the virgin’s conceiving and bringing forth a Son; by a voice from heaven, proclaiming Christ the Father’s only begotten Son, in whom he was well pleased.

SO THAT THE SONS OF ISRAEL COULD NOT LOOK INTENTLY AT THE FACE OF MOSES BECAUSE OF THE GLORY OF HIS FACE, FADING AS IT WAS: hoste me dunasthai (PPN) atenisai (AAN) tous huious Israel eis to prosopon Mouseos dia ten doxan tou prosopou autou ten katargoumenen (PPPFSA): (So that: Ex 34:29-35 Lk 9:29, 30, 31 Ac 6:15) (2Co 3:10,11,14 Ro 10:4 1Co 13:10)

The proof of that the glory is borne out by the fact that the children of Israel could not look at the the face of Moses because of the glory.

The sons of Israel - This phrase appears some 645 times in Scripture as a generic (characteristic of a whole group) name for the entire nation of Israel, both male and female (first OT use Ge 32:32, first NT use Mt 27:9, Lk 1:16).

Moses records...

 It came about when Moses was coming down from Mount Sinai (and the two tablets of the testimony were in Moses’ hand as he was coming down from the mountain), that Moses did not know that the skin of his face shone because of his speaking with Him. So when Aaron and all the sons of Israel saw Moses, behold, the skin of his face shone (radiated light, was luminous, sent out light), and they were afraid to come near him. (Ex 34:29, 30)

Could (1410) (dunamai [word study\) conveys the basic meaning of that which has the inherent ability to do something or accomplish some end. Thus dunamai means to be able to, to be capable of, to be strong enough to do or to have power to do something. The present tense indicates that they continually were not able to look intently on Moses' face.

Could not look intently - The sons of Israel could not keep their eyes fixed on Moses because of the splendor and radiance of his face which was a reflection of the glory of the Lord.

Look intently (816) (atenizo from a = intensifies + teino = stretch, strain) means to fix one's gaze on something or stare at something. Gaze earnestly. Look straight at something.

This same verb describes the Jews in the synagogue able to look on the glory of Him Who was full of grace and truth (Jn 1:14), Luke recording...

And He closed the book, gave it back to the attendant and sat down; and the eyes of all in the synagogue were fixed on Him.  (Lk 4:20)

Atenizo - 14x in 14v in NAS:  fixed(1), fixed...gaze(4), fixing...gaze(2), gaze(1), gazed intently(1), gazing intently(1), look intently(2), looking intently(2). Not in the Septuagint.
 

Luke 4:20 - see above

Luke 22:56 And a servant-girl, seeing him as he sat in the firelight and looking intently at him, said, "This man was with Him too."

Acts 1:10 And as they were gazing intently into the sky while He was going, behold, two men in white clothing stood beside them.

Acts 3:4 But Peter, along with John, fixed his gaze on him and said, "Look at us!"

Acts 3:12 But when Peter saw this, he replied to the people, "Men of Israel, why are you amazed at this, or why do you gaze at us, as if by our own power or piety we had made him walk?

Acts 6:15 And fixing their gaze on him, all who were sitting in the Council saw his face like the face of an angel.

Acts 7:55 But being full of the Holy Spirit, he gazed intently into heaven and saw the glory of God, and Jesus standing at the right hand of God;

Acts 10:4 And fixing his gaze on him and being much alarmed, he said, "What is it, Lord?" And he said to him, "Your prayers and alms have ascended as a memorial before God.

Acts 11:6 and when I had fixed my gaze on it and was observing it I saw the four-footed animals of the earth and the wild beasts and the crawling creatures and the birds of the air.

Acts 13:9 But Saul, who was also known as Paul, filled with the Holy Spirit, fixed his gaze on him,

Acts 14:9 This man was listening to Paul as he spoke, who, when he had fixed his gaze on him and had seen that he had faith to be made well,

Acts 23:1  Paul, looking intently at the Council, said, "Brethren, I have lived my life with a perfectly good conscience before God up to this day."

2 Corinthians 3:7  But if the ministry of death, in letters engraved on stones, came with glory, so that the sons of Israel could not look intently at the face of Moses because of the glory of his face, fading as it was,

2 Corinthians 3:13 and are not like Moses, who used to put a veil over his face so that the sons of Israel would not look intently at the end of what was fading away.

The glory of his face - Moses the mediator of the Old Covenant manifested a degree of glory, but it was a glory that was fading while verse 8 indicates the glory of the New Covenant was greater.

Fading - In 2Cor 3:7,11, 13 the verb the NAS translates "fade" is katargeo which means to render inoperative or ineffective. The glory of Moses’ face was "rendered ineffective" in the sense that its brightness was diminishing and relatively speaking lasted only a short time.

Fading (2673)(katargeo [word study] from kata = intensifies meaning + argeo = to be idle or inactive from argos = ineffective, idle, inactive from  a = without + érgon = work) literally means to reduce to inactivity. To cause something to come to an end. The idea is to make the power or force of something ineffective and NET Bible picks up on this sense rendering it as "a glory which was made ineffective." Young's Literal renders the glory as "being made useless." The present tense signifies the glory was continually fading which points to the temporary nature of the Old Covenant.

Katargeo [word study] is a key verb in this chapter (5 uses) and in the Corinthian epistles, accounting for almost one half of the 27 NT uses - Lk 13:7; Ro 3:3, 31; 4:14; 6:6; 7:2, 6; 1Co 1:28; 2:6; 6:13; 13:8 (2x), 1Co 13:10, 11; 15:24, 26; 2Co 3:7, 11, 13, 14; Ga 3:17; 5:4, 11; Ep 2:15; 2Th 2:8; 2Ti 1:10; He 2:14. NAS translates it - abolished(4), abolishing(1), bring to an end(1), did away(1), do away(1), done away(4), fades away(1), fading(1), fading away(1), nullified(1), nullify(4), passing away(1), released(2), removed(1), render powerless(1), severed(1), use(1).

Paul will pick continue his discussion of the fading glory of the Old Covenant in 2Co 3:11.

Steve Zeisler...
 

Paul says that Moses' face had a shining quality about it because Moses had stood in the presence of God, and the power and presence of God made his face shine, just as the sun makes the face of the moon to shine. The people were amazed at the glory of Moses' face, but it was a fading glory.

Further on in 2Co 4:6 we read

For God, who said, 'Let light shine out of darkness,' made his light shine in our hearts to give us the light of the knowledge of the glory of God in the face of Christ.

There is a second face in this passage -- the face of Jesus Christ -- which is intrinsically glorious and His face does not reflect anyone else's glory. And in the New Covenant, light is implanted within our hearts so that we become like the sun -- much more remarkable (Ed: "more glorious", in fact going from "glory to glory" 2Co 3:18-note) than the moon, inwardly generated, radiating out from our core -- life itself (Ed: cp Col 3:4-note which reads literally "Christ our life") -- not responding to God from a distance, but responding to Him because He has taken up residence inside us (Col 1:27-note, Gal 2:20-note).

We have a choice to make (2Co 6:2). The law of God written on stone is unchangeable. We can turn to the Old Covenant and read the inflexible, immutable, external-to-us appeal any time we want. It calls forth great effort, but stands ready to judge even the smallest failure. God can be known on this basis. We can do our best and fool the people around us concerning our failures-that is an option that always remains available to us-or we can have the Old Covenant do its work of condemning us (ministry of condemnation 2Co 3:9), making us cry, "Lord, I'm an utter failure." Then, having been condemned, we can appeal to the Savior Who in a love relationship takes up residence inside us.

In Colossians 1, Paul says,

The mystery that has been kept hidden for ages and generations is now disclosed to the saints. To them God has chosen to make known among the Gentiles the glorious riches of this ministry, which is Christ in you, the hope of glory. (Col 1:27-note, Gal 2:20-note).

I urge upon all of you a decision. To the degree that God has made clear to you that you have lived your life with everything coming from you, keeping Him at a distance---choose the New Covenant. Choose the life in which the Lord God resides within, in which everything begins with a love relationship, where failures are no longer measured, where God gets the honor. Then the watching world has a reason to hope for glory.  (Great and Lasting Glory)

Guzik...
 

Exodus 34:29-35 (see above) describes the face of Moses and how he would veil it after speaking to the people. As glorious as the radiant face of Moses was, it was a fading glory: which glory was passing away. The glory of the old covenant shining through the face of Moses was a fading glory, but the glory of the new covenant endures without fading.

Joseph Beet comments...
 

Without doubt the brightness on Moses’ face did not continue, but gradually and totally vanished. This is very suggestive. Though the brightness was more than Israel could bear, it was nevertheless a fading glory. (A Commentary on St. Paul's Epistles to the Corinthians)

Warren Wiersbe emphasizes that the legalistic teachers would...

magnify the glory of the Law and minimize its weaknesses. In his letter to the Galatian churches, Paul pointed out the deficiencies of the Law: the Law cannot justify the lost sinner (Gal. 2:16), give a sinner righteousness (Gal 2:21), give the Holy Spirit (Gal 3:2), give an inheritance (Gal 3:18), give life (Gal 3:21), or give freedom (Gal 4:8, 9, 10). The glory of the Law is really the glory of a ministry of death. (Wiersbe, W: Bible Exposition Commentary - New Testament. 1989. Victor or Logos or Wordsearch)
 

HOW WILL THE MINISTRY OF THE SPIRIT FAIL TO BE EVEN MORE WITH GLORY?: pos ouchi mallon e diakonia tou pneumatos estai (3SFMI) en doxe?: (2Co 3:6,17 11:4 Isa 11:2 44:3 59:21 Joel 2:28,29 Jn 1:17 7:39 Ac 2:17,18,32,33 Ro 8:9-16 1Co 3:16 12:4-11 Ga 3:2-5,14 Ga 5:5,22,23 Eph 2:18 2Th 2:13 1Pe 1:2 Jude 1:19,20)

As is Paul's frequent practice in his epistles, he asks his readers a rhetorical question, that is, a question asked merely for effect with no answer expected. In this passage Paul is completing the comparison he began in 2Co 3:7. In other words, if the Law of Moses came with such splendor, how much greater is the splendor of the ministry of the Spirit. The question assumes an affirmative answer for clearly the ministry of the Spirit brings more glory than the ministry of Moses and the Old Covenant.

The ministry of the Spirit - This is another "synonym" for the New Covenant (which also equates with "the ministry of the Gospel" according to Joseph Beet), the "centerpiece" of the New Covenant being the permanently indwelling Spirit in all who enter the New Covenant. In other words, the New Covenant is aptly called the ministry of the Spirit because it results in the giving of the Holy Spirit to all who enter it by grace through faith (cp Ro 8:9-note, 1Co 6:19-note)

Puritan writer Thomas Watson says that...

The ministry of the gospel is called the ministry of the Spirit in 2 Corinthians 3:8, because the Spirit of God ordinarily makes use of this to work grace. This ministry of the Spirit is to be preferred before the ministry of angels. (The Beauty of Grace)

Ministry (1248)(diakonia) means the rendering or assistance or help by performing certain duties, often of a humble or menial nature serve, including such  mundane activities as waiting on tables or caring for household needs—activities without apparent dignity

Be even more with glory - Literally the future tense is used ("will be...with glory") for when the Law of Moses was given, the New Covenant was clearly a future event. Obviously at the time Paul wrote the new covenant was a present reality. The Law written on stone could only condemn. The Law written on the heart by the Holy Spirit brought salvation. Clearly the New Covenant has even more glory than the Old.

John MacArthur notes that...

The Old Covenant is good in that it commands righteousness. The New Covenant is better in that it confers righteousness. The Old Covenant made a person a hearer of the truth. The New Covenant makes a person a doer of the truth...So the old covenant was never intended to save, it was an inferior covenant to the new covenant to begin with it because it was a non-saving covenant. Then, however, when an Old Testament Jew was saved by grace through faith, all of a sudden that Law, that moral law which once was a killer to him became a path of blessing and he had an attitude like David (Ps119:97-note) who said "O how I love Thy law! It is my meditation all the day." Now, instead of the Law being a "killer", the Law was a path of life and blessing...sweeter to him than honey in the honeycomb, more precious than gold. It wasn't that his attitude toward the Law saved him, it was that his salvation changed his attitude toward the Law.  (The Glory of the New Covenant, Part 4)

Ray Stedman comments that Paul calls the Old Covenant...

the ministry of death, a fading glory, it does not last. But when you discover a new principle, a principle of God-dependence, that in using your native skills, abilities, and training, God nevertheless will be at work (cp Php 2:12-note, Php 2:13-note). In depending on that (Ed: he is referring to the New Covenant ministry of the Spirit), there is an excitement and a glory that is greater than the one you feel when you want to show off what you can do (cp Jn 15:5). (Have you got What it Takes 2 Corinthians 3:1-11)

Steve Zeisler explains the ministry of the Spirit and the New Covenant as...

the Spirit of God, writing on tablets of human hearts (Je 31:33, 34, 2Co 3:3-note, He 8:10-note He 10:16-note), living inside (Ro 8:9-note, 1Co 6:19-note), making us different people from inside out (2Co 3:18-note), offering us power to do what we could not do before (Gal 5:16-note cp "freedom/liberty" = 2Co 3:17-note), changing us so that we don't even want to do what we did before (Php 2:13NLT-note, Ezek 36:26, 27). (Great and Lasting Glory)

Joseph Beet has an interesting thought on the "future tense glory"...

From the supernatural brightness which encompassed Moses as he gave to Israel the death-bringing letters, Paul infers that a still greater splendor awaits those through whom is imparted the life-giving Spirit. And, since no such splendor surrounds them now, he speaks of it as something which shall be. He refers (cp. "hope" in 2Co 3:12) to the brightness in the world to come of those who (Da 12:3) now "turn many to righteousness." (A Commentary on St. Paul's Epistles to the Corinthians)

Wiersbe commenting on even more with glory writes...

When Moses descended from the mountain, after conversing with God, his face shone with the glory of God (Ex 34:30). This was a part of the glory of the giving of the Law, and it certainly impressed the people. Paul then argued from the lesser to the greater: if there was glory in the giving of a Law which brought death, how much more glory is there in a ministry that brings life! (Wiersbe, W: Bible Exposition Commentary - New Testament. 1989. Victor or Logos or Wordsearch)

Samuel Davies...

However little the gospel of Christ is esteemed in the world, it is certainly the most gracious and important dispensation of God towards sinful men, or else our Bible is mere fantasy and fable; for the Bible speaks of it with the highest encomiums, and the sacred writers are often in transports when they mention it. It is called: the gospel of the grace of God, Acts 20:24;  the gospel of salvation, Ephesians 1:13; the glorious gospel, or, the gospel of the glory of Christ, 2 Corinthians 4:4; the gospel of peace, Ephesians 6:15. Nay, its very name has something endearing in the sound, "good tidings," "joyful news". It is the wisdom of God in a mystery, 1Corinthians 2:7; the mystery which had been hidden from ages and from generations, Col. 1:26; the ministry of the Spirit, and of righteousness, which far exceeds all former dispensations in glory. 2 Corinthians 3:8, 9. (The Nature of Justification)

Here is a translation of verses 7-8 in one African language...

The old Laws were written on stones, and the glory of God was seen at that time. The people of Israel could not look [long] at the face of Moses, because it was shining strongly, even though this glory did not last. Therefore, if the Laws whose job is to bring death had glory like that, then the work of the Spirit of God will have greater glory than the Laws. Is this not true? (UBS Handbook)

J C Philpot on the Ministry of the Spirit...

 The first leading feature of the gospel is, that it is the ministry of the Spirit; that is, through it and by it the Holy Spirit is promised and communicated. Thus Paul asks the Galatians, "This only would I learn of you—have you received the Spirit by the works of the law or by the hearing of faith?" (Gal 3:2) The "hearing of faith" means that hearing of the gospel with the believing heart, whereby it becomes "the power of God unto salvation," (Ro 1:16) when it comes "not in word only, but also in power, and in the Holy Spirit, and in much assurance." (1Th 1:5) In this sense the gospel is the ministry or service of the blessed Spirit, that gracious and holy Teacher using it as a means of conveying himself into the heart. When our blessed Lord rose from the dead, and ascended on high, he "received gifts for men." (Ps 68:18) The prime and chief of these gifts was the Holy Spirit, which, being promised Him by the Father as a part of the reward of His humiliation, sufferings, and death, is therefore called "the promise of the Father;" (Acts 1:4KJV) "Behold, I send the promise of the Father upon you;" (Lk 24:49) "the promise of the Holy Spirit;" (Acts 2:33) and "the Holy Spirit of promise;" (Ep 1:13) the meaning of all these expressions being that the Holy Spirit, with all His gifts and graces, is the promised Comforter, Teacher, and inward Intercessor of all to whom the gospel comes with power.

Thus the chief glory of the Gospel is, that it is the "ministry of the Spirit." If, then, the precept be an integral part of the gospel, it must also be a part of the ministry of the Spirit. Not that the precept communicates the Spirit, as do the truths, the promises, the invitations, the declarations of the gospel. These instrumentally communicate the Spirit, whereas the precept does but follow it, and acts in union and harmony with it. Let us explain this point a little more clearly. When a Gospel truth, such as "The blood of Jesus Christ cleanses from all sin;" or a Gospel declaration, as "He who believes on me has everlasting life;" or a Gospel promise, as, "I will not leave you comfortless, I will come unto you," or a Gospel invitation—"If any man thirsts, let him come to me and drink," comes to the heart with a divine power, the Holy Spirit is as if communicated thereby; for He comes into the heart through that truth, declaration, promise, invitation, etc.

But He does not, at least not usually, come into the heart through the precept, for the precept follows as the fruit and effect of His coming. Yet as the fruit and effect of his coming, the spirit of the precept is in the fullest harmony and union with the whole tenor and current of the gospel. Thus there is not a single precept which is not in harmony with the gifts and graces of the Holy Spirit. May we use a figure to illustrate this? Here is a piece of beautiful music—the master-piece of an eminent composer, say Handel's Hallelujah Chorus. What do you see? Several sheets of musical characters, as notes, etc., which you may or may not read and understand. But while in the mere score, there is no music in them—at least, the body is there, but not the soul of music. Now, hear this score played and sung as intended. What a soul is put into it, and what harmony! Among thousands of notes you will not hear a jarring sound. So with the precepts. Dead in the letter, when a soul is breathed into them by the Holy Spirit, they all are animated as with one harmonious voice, every note being in perfect unison with the Gospel of the grace of God. (The Precepts of the Word of God)

MINISTRY OF SPIRIT
SANCTIFICATION

The ministry of the Spirit includes causing us to be born again and then causing us to grow in grace and the knowledge of our Lord and Savior Christ Jesus. Bradford Mullen summarizes the Holy Spirit's role in sanctification (Note: I've also included some of his additional thoughts from his excellent article on sanctification) ...

Paul continues his argument from lesser (Old Covenant) to greater (New Covenant).

For (gar) explains or continues Paul's argument (it restates it using slightly different wording) that the glory of the New Covenant surpasses the fading glory of the Old Covenant. 

If (ei) does not express doubt and the Wuest translation conveys the sense of this conjunction "for in view of the fact that".

Ministry of condemnation - MacArthur calls it "the ministry of judgment, the ministry of doom, the ministry of damnation". Why? Because no one can obey the law perfectly (Jas 2:10). This description amplifies Paul's previous statement that the letter kills (2Co 3:6).

Moses declared the OT equivalent of James 2:10, writing...

‘Cursed is he who does not confirm the words of this law by doing them.’ And all the people shall say, ‘Amen.’ (Dt 27:26, quoted by Paul in Gal 3:10).

Comment: This final curse is the last of the twelve curses (Deut 27:1-26 consists only of the curses) and this last curse sums up all the previous ones. The point is that God required and the Law demanded total, perfect obedience something accomplished by only one Man, the Man Christ Jesus (cp 2Co 5:21, He 4:15-note). Note the response of the sons of Israel was "Amen" (12 times they replied "Amen" each time solemnly saying they agreed that the curses were just and valid! - see word study on "Amen") which was their way of saying they would be obedient, a promise they almost immediately broke! As a result they came under the condemnation of the Law (cp Ezek 18:4, Ro 3:19-note, Ro 3:20-note, Ro 6:23-note).

Condemnation (2633) (katakrisis from kata = against + krino = judge) refers to a judicial verdict involving a penalty. It refers to  the judicial act of declaring one guilty, and dooming him to punishment. This was the effect of the Old Covenant.

Ray Stedman explains the ministry of condemnation this way...

Everybody who tries to live a life that is pleasing to God by self-effort always discovers that he never quite makes it because he never knows when he has done enough. A lady said to me just last week, "When I go to bed at night I often wonder if I had tried just a little harder maybe I could have done something that would have made God happy." But she never made it. Every night there was that feeling of, "I didn't quite measure up today." That is the ministry of condemnation. It is the result of trying to do it on your own resources, by your own efforts.  (Have you got What it Takes 2 Corinthians 3:1-11)

Expositor's Bible Commentary...

Well then, argues Paul, if such glory attended the giving of the law under the ministry or administration that brought death and condemns men, how much more glorious will be the ministry of the Spirit that brings righteousness! What was a distinctive and positive feature of the old order must also characterize the new economy, but in greater measure. (Ibid)

Beet comments...

The Law pronounces the condemnation (De 27:26) of all who disobey it; and therefore of all men. For none can obey it. Consequently, the only immediate effect of the Law is that just so far as we know it we are condemned by it. For "through law comes understanding of sin": Ro 3:20. By conveying to men such a law Moses was a minister of condemnation. (A Commentary on St. Paul's Epistles to the Corinthians)

 MUCH MORE DOES THE MINISTRY OF RIGHTEOUSNESS ABOUND IN GLORY: pollo mallon perisseuei (3SPAI) e diakonia tes dikaiosunes doxe:  (Righteousness: 2Co 5:21 Isa 46:13 Jer 23:6 Ro 1:17 3:21,22 4:11 5:15-21 10:3-10 1Co 1:30 Ga 5:4,5 Php 3:9 2Pe 1:1) (Abound: 2Co 3:10,11 1Co 15:41 Heb 3:5,6)

Much more - Going from the lesser, fading glory of the Law to the continually superabounding glory of the Gospel.

The ministry of righteousness - Another synonym for the New Covenant which is proclaimed in the Gospel of Jesus Christ.

Charles Simeon explains that...

the Gospel is called a ministry of righteousness because it reveals a righteousness commensurate with all the demands of the law, and offers that righteousness to every man who will believe in Christ. It declares that “Christ himself is the end of the law for righteousness to every one that believeth” (Ro 10:4) and that the law was given as a ministration of death on purpose to shut men up to this righteousness, and to constrain them to seek salvation in the way provided for them (Gal 3:22, 23)...

Thus the Gospel supplies what the law knew nothing of. We have before said, that the law spake nothing of pardon to the guilty, or of strength to the weak: but the Gospel administers both; and that too in such an abundant measure, as is adequate to the necessities of the whole world: it ministers righteousness sufficient to justify the most guilty sinner upon earth; and imparts the Spirit, so that the weakest may be more than conqueror over all the enemies of his soul. (Read his excellent sermon The Glory of the Gospel Above that of the Law)

Adam Clarke explains the much more glory noting that...

it is the Gospel (New Covenant) that does what the law (Old Covenant) signified (or symbolized or pointed toward); and forasmuch as the performance of a promise is greater than the promise itself, and the substance of a man is greater than the shadow projected by that substance (cp Col 2:17-note); so is the Gospel of Jesus Christ greater than the law, with all its promises, types, ceremonies, and shadows.

Ruth Bryan...

The ministry of condemnation was glorious, when it pleased the Lord to bruise Him. But the ministry of righteousness exceeds in glory--when the blessed Spirit brings near His righteousness, yes, puts it on the soul, saying, "Bring forth the best robe, and put it on him!" (Lk 15:22) It is also exceedingly glorious when the righteous Father welcomes the prodigal with the kiss of everlasting love, being well pleased for His righteousness' sake (Lk 15:22); and when "the Lord our righteousness sees of the travail of His soul and is satisfied," (Is 53:11) saying, "You are all beautiful, my love! There is no spot in you!" (Song 4:7) Then also is the poor soul richly satisfied, saying, "In the Lord I have righteousness and strength!" (Is 45:24) "I will make mention of your righteousness, even of yours alone." (Ps 71:16) This is, indeed, a glorious ministry of righteousness, and is part of the abundance of Your house, my King and my God. Here is food for hungry souls who have long been starving on the husks of self (self-righteousness) and here is clothing for the naked soul (Re 3:17), who has been into the "stripping-room," and had the filthy rags (Is 64:6), and all the adornments of self stripped off! O my precious friend, it is a mercy to be made and kept poor enough for Jesus to be all. (The preciousness of Christ unfathomable and ever new)

Paul was as enslaved in the practice of the Old Covenant Law as any man (Php 3:4, 5, 6-note) but when he met Jesus, the Covenant Messenger (Mal 3:1), he began to experience a quality of life and liberty so much more glorious that under the Old Covenant that it led him to exclaim...

But whatever things were gain to me (while he was under the Law, trying to merit righteousness, but only experiencing condemnation), those things I have counted as loss for the sake of Christ. 8 More than that, I count all things to be loss in view of the surpassing value of knowing Christ Jesus my Lord, for Whom I have suffered the loss of all things, and count them but rubbish in order that I may gain Christ, 9 and may be found in Him, not having a righteousness of my own derived from the Law, but that (righteousness) which is through faith in Christ, the righteousness which comes from God on the basis of faith (Php 3:7, 8-note, Php 3:9-note)

RIGHTEOUSNESS:
POSITIONAL AND PROGRESSIVE

Clarke interprets the ministry of righteousness as

The Gospel, the grand business of which was to proclaim the doctrine of justification; and to show how God could be just and yet the justifier of him who believeth in Jesus.

Comment: As alluded to above in the discussion of the ministry of the Spirit  (note), there is positional righteousness (justification by grace through faith, a one time event, past tense salvation [Tenses of Salvation], perfect righteousness before God because of the crediting of Christ's perfect righteousness to our account independent of any obedience to the Law on our part for it exists in Christ alone - 1Co 1:30 Php 3:9-note Ro 3:20-note Je 23:6 2Co 5:21) and there is also "progressive" or experiential righteousness (progressive sanctification, growth in holiness and Christ-likeness, an ongoing process in this present life but also by grace through faith not works or self effort, often called present tense salvation). The ministry of righteousness then is that work of the Gospel mediated by the Word and the Spirit which first causes us to be born again (justified = declared positionally righteous) and then (mediated also by the Word and the Spirit - eg 2Co 3:18-note, Jn 17:17, Ro 15:16 et al) the lifelong process of growth in holiness (sanctification = daily being made experientially righteous). It should be noted that one cannot dissociate positional from progressive righteousness, as some falsely teach even in evangelical circles saying that one can be born again and thereafter exhibit no changed life. This is not what the Bible teaches and is clearly the deceptive, damning doctrine of demons!

Ministry of righteousness - ("the ministry that produces and fosters righteous living and right standing with God" Amplified) As discussed in the preceding comment, the New Covenant is marked by and leads to a righteous lifestyle for those who enter into it by grace through faith. As a corollary - if one says they have entered the New Covenant and yet they fail to exhibit any change in lifestyle and/or no tendency toward righteousness or "right living" (as their direction not perfection! cp 1Jn 1:8), they may well be professors of Christ, rather than possessors of His holy life and His Holy Spirit. The Spirit of holiness indwelling a believer urges and impels the believer toward righteousness and holiness and godliness, not toward unrighteousness, unholiness and ungodliness (cp the instructing, "child rearing" effect of the "grace of God" in Titus 2:12-note).

Paul exhorted the Corinthians...

Test (peirazo in the present imperative = command to make this your continual practice) yourselves (Not others but yourselves! cp Mt 7:1-note, Mt 7:5-note) to see if you are in the faith; examine (dokimazo also present imperative) yourselves! Or do you not recognize this about yourselves, that Jesus Christ is in you-- unless indeed you fail the test (adokimos)? (2Cor 13:5-note)

Comment: Be careful! Remember that God is the ultimate Judge of the authenticity of the salvation of others, not us. Believers must avoid the temptation to be critical or judgmental of another person's life, for we cannot see their heart. It is one thing to urge one we suspect to be a professor to pursue holiness (He 12:14KJV-note), but ultimately it is up to God and His Spirit to cause the new birth (Jn 3:3, 5, 6, 7, 8, cp 1Pe 1:3-note, 1Pe 1:23-note) and to place the desire and that power (Php 2:12-note, Php 2:13-note) in an individual's life.

Righteousness (1343)(dikaiosune from dikaios [word study] = being proper or right in the sense of being fully justified being or in accordance with what God requires) is the quality of being upright. In its simplest sense dikaiosune conveys the idea of conformity to a standard or norm and in Biblical terms the "standard" is God and His perfect, holy character. In this sense righteousness is the opposite of hamartia (sin), which is defined as missing of the mark set by God.

"I have loved you, I have forgiven you, I have cleansed you. You are my dearly beloved child. I intend to use you; you are part of my program; your life is significant. There is nothing more you can add to that (cp Col 2:10-note). Now, on that basis, with the security of that acceptance (cp Ep 1:6KJV-note), go back to your work."

Abound (surpass, overflow) (4052) (perisseuo from perissos = abundant, exceeding some number, measure, rank or need, over and above) means  to cause to superabound, to be superfluous, to overflow, to be in affluence, to excel or to be in abundance with the implication of being considerably more than what would be expected. Perisseuo conveys the idea of exceeding the requirements, which in a sense is what the New Covenant did. God's requirement was perfect obedience in order to attain righteousness or be justified.

William Plummer (1867) writes that...

For (gar) explains and supports Paul's argument from lesser glory (Old Covenant) to greater glory (New Covenant) mentioned in 2Co 3:9.

For indeed what had glory - The Old Covenant had glory. The glory on the face of Moses, although temporary, was real glory. Not only did Moses' face reflect glory, the Tabernacle (established in concordance with the Old Covenant regulations) was the site of God's Shekinah glory which ceased with the destruction of the Solomon's temple.

Had glory...has no glory (1392)(doxazo) means to cause to have great splendor.

Both verbs are in the perfect tense and the latter (has no glory) indicates that this loss of splendor of the Old Covenant is a permanent condition.

In this case - In the case of the comparison of the Old to the New Covenant.

What had glory has no glory - Clearly the Old Covenant had glory (2Co 3:7 and the next verse 2Co 3:11) but that glory is as if it is no glory in comparison the surpassing glory of the New Covenant. The analogy in nature is the glory of the sun compared to the glory of the moon, for when the sun rises, the moon begins to fade and eventually disappear. The writer of Hebrews states that...

When He said, "A new covenant, (added by translators)" He has made the first (covenant) obsolete. But whatever is becoming obsolete and growing old is ready to disappear. (He 8:13)

Rob Salvato illustrates the "no glory" of the Old Covenant...

The law is a mirror. It is not a bar of soap. We look in the mirror to see the condition of our countenance. I need a make over – I need a shower I am dirty! It’s the soap which cleanses US of our dirt. The law is a mirror. not soap. The law is not a surgeon, who can remove, by his skills, a cancer. The law is simply gives us the diagnosis. The office of the law is to show us the disease in such a way that it shows us no hope of a cure! The New Covenant brings a remedy to those who are past hope. The glory of the New Covenant is greater because it provides a way for man to become RIGHTEOUS in the site of God through faith in Jesus Christ – That is what made this a greater glory! (From Glory to Greater Glory)

Glory that surpasses it - More literally "the surpassing glory", the "throwing beyond" glory.

Surpasses (5235) (huperballo from huper = above + ballo = cast, put) literally means throw beyond the usual mark which came to describe a degree which exceeds extraordinary. Synonyms include exceeding, extraordinary, extreme, supreme, far more, much greater, to a far greater degree. The present tense signifies the continually surpassing glory of the New Covenant (alluding to its never ending character) in comparison to the Old Covenant.

Robertson...

Christ as the Sun of Righteousness (Malachi 4:2) has thrown Moses in the shade. Compare the claims of superiority by Christ in Matthew 5 to 7 (the Sermon on the Mount).

Beet comments that...

The Old Covenant belongs to the category of objects glorious in themselves which lose their glory by the surpassing splendor of some brighter object. Just so the moon is as bright after sunrise as before: but, practically, its brightness is completely set aside by that of the sun. It is so in the matter of the Old Covenant.

In it is illustrated the general principle,
the glorified is not glorified
because of the surpassing glory.

The brightness of Moses’ face revealed the splendor of his ministry. And while we look at his ministry alone, amid the darkness of surrounding night (Ed: cp the spiritual darkness of the unsaved world), it is in our eyes covered with glory. But when we compare it with the ministry which proclaims righteousness for men whom the Law condemned, and which imparts, not letters graven on stones, but the abiding presence of the life-giving Spirit, the glory of the former covenant fades utterly, and we think only of the greater splendor of the ministry of the New Covenant. This strengthens immensely the argument of 2Co 3:7, 8. If a supernatural brightness attested the grandeur of the Old Covenant, and if the Old Covenant now sinks into insignificance in presence of the New, surely an infinite splendor belongs to, and therefore awaits, the ministry of the New Covenant. For nothing less than infinite splendor can throw into the shade the splendor of the Old Covenant. (A Commentary on St. Paul's Epistles to the Corinthians)

John MacArthur addresses the question that many ask and that is...

"Well is God's moral law still important?" Sure it is because God's moral law is still the...is still the rock which has to break the sinner's back. And we have to preach that Law and uphold that Law. And by the way, the moral law is repeated in the New Testament, right? The civil law is set aside...Gentiles and Jews are made one. Ceremonial law is set aside -- no more Sabbaths and new moons and feasts and sacrificial system, the temple is destroyed, no more sacrifices...that's all done away with. But the moral law is repeated and recited in the New Testament and it is again reiterated and brought before the sinner to show him his sin. But if the Old Covenant was by itself, it would be absolutely useless, for even the virtuous reflection of the holiness of God is useless to save. The New Covenant comes and by grace through faith provides what the Old Covenant could not provide.

THE NEW COVENANT
IS PERMANENT

For if -  For since it is true is the idea (the Law did have glory). Continuing his lesser-to-greater argument, Paul explains or gives a reason for the greater splendor suggested in the preceding verse.

That which fades away - Referring to the ministry of the Old Covenant of Law, the ministry of condemnation. The Old Covenant is valid (but see MacArthur's clarifying comment) only until the New Covenant comes with the liberating, life giving Gospel (Gal 3:22 - where "Scripture" in context = "Old Covenant", Ro 10:4-note, Ro 6:14-note). In 2Co 3:7 the same verb katargeo (fading away) refers to the glory of Moses’ face, whereas here fades away refers to the glory of the Old Covenant.

The fading of the glory on Moses' face was in a sense an acted out prophecy, in other words, the facial fading preceding and predicting the future fading of the Old Covenant.

Fades (2673)(katargeo from kata = intensifies meaning + argeo = to be idle or inactive from argos = ineffective, idle, inactive from  a = without + érgon = work) literally means to reduce to inactivity or to cause something to come to an end, in this case the Old Covenant.  The present tense signifies the glory was continually fading emphasizing the temporary nature of the Old Covenant. It is in process of disappearing.

Ryrie comments that...

There is no question that the law was glorious for its time and purpose, but its temporariness and limited purpose caused that glory to fade in the blazing light of the grace of Christ, which has as its eternal purpose the bringing of many sons into glory (John 1:17; Heb. 2:10).

John MacArthur explains that...

The Law was no permanent answer. The Law was no final solution. The Law was never intended to be the last word on the plight of sinners. The Law never could save. It can't be the last word. I remember on one occasion when I was in Israel many years ago and I stayed in a hotel right adjacent to a synagogue, my room was right about as far as I could reach my arm to touch this synagogue and it was...it was on Shabbat and they were having this worship and I heard it hour after hour after hour and, of course, the realization that these people are locked in to the old covenant. They will not allow the new covenant. They will not tolerate it. And if you introduce it to them, they become violently aggressive and agitated about it in their rejection. And you want to say to them, "But...but...but the Law was never the last word on the plight of sinners, it can't save. It was never to be the full final revelation of God's redemptive purpose and the means by which righteousness could be provided. It only pointed to something greater."

It was not adequate, it was not permanent. It could prescribe what men ought to do, but it couldn't enable them to do it. The old covenant could provide a basis of damnation but not of salvation, a basis of condemnation but not of justification, a basis of culpability but not purity. Something had to be added.

You say, "Well did the Jews know it was coming? Were they ever told?" Sure, Jeremiah made it as clear...as crystal clear as it could be made. Jer 31:31, 32, 33, 34...They should have known that the old covenant wasn't the last. The contrast is between what is transitory and passing and what is lasting and eternal. What Moses stood for was glorious but passing away. The day was bound to come when its splendor would vanish. The new covenant, however, comes with a pledge of eternality. The new covenant doesn't fade away....

The new covenant is the last word, salvation by grace through faith. The ministry of death and condemnation had a glory, it was designed by God, it was holy, just and good. It established the standard of righteousness. And for believers, for those forgiven by God and saved, it was a path of blessing. But the New Testament has a greater glory. The new covenant has a greater glory. And without the new covenant, the old covenant would have just catapulted the whole human race into hell....

But let's take a true Jew who really believed. What would he do? He would come to God, repentant, pleading for grace and pleading for mercy. He saw the ceremonial law as symbolic of God's provision for him somewhere down the future. He knew God would provide. He knew God would be gracious and God would be merciful because that's the kind of God He was. And he cast himself on God's mercy and God's grace. And he would be redeemed based upon what Christ would do in his behalf. But for most Jews, the vast majority, apart from that true remnant, they disobeyed the Law offered, no genuine repentance, exercised no saving faith in God, depended not on God's grace but on their works keeping the external ceremonial religion and that was really a killer. And along came the prophets and constantly called them to repentance.  That's always the message. It boggles my mind how that people can say today that we don't have to preach repentance. It's always been the message....

New covenant ministry will continue and never be replaced because there's no more to do, there's no more to say. It's all been done in Christ. He has accomplished once forever the redemption of His people. There is no higher truth, that's it. Oh, we'll get new understanding of the richness of the gospel as we grow but we'll never get beyond the gospel, we'll never get beyond the new covenant. There's nothing beyond it. (The Glory of the New Covenant, Part 4)

That which remains - This phrase refers to the New Covenant. The Good News. The Gospel of grace.

Beet comments...

In the history of the world, as in the experience of each individual God speaks first in the form of Law, "Do this or die." When we hear the good news, "He that believes shall not die," the voice of condemnation loses its dread power, and comes to nought. But the good news of life will remain sounding in our ears for ever. Paul argues, "If the temporary dispensation was accompanied by splendour, of which splendour the brightness on Moses’ face was a conspicuous example, surely the abiding voice of the Gospel is or will be surrounded by still greater splendour." [Notice the appropriate use of dia [through, with] and en [in],  as in Ro 1:2, for the temporary and the permanent.] With the passing nature of the Covenant of which he was Mediator, the passing brightness of Moses’ face was in beautiful though incidental agreement. Even the little outward details of the two Covenants were in harmony with their inward essence. (A Commentary on St. Paul's Epistles to the Corinthians)

Comment: Bernard agrees with Beet's comments on the prepositions, explaining that dia (with) implies transience while en (in) implies permanence.

Ray Stedman has an different interpretation/application of this section explaining that...

Paul is talking about himself, looking back to the days when he counted on his background, his skill, his sharp mind and dedicated heart for success (Ed: When he was under the Old Covenant of the Law, the ministry of death and of condemnation). He is saying,

"I have come now to understand that God at work in me can do so much more than I could ever have done (Ed: cp Gal 2:20-note, 1Co 15:10-note, Php 4:13-note). I have come to understand that Christ's work in me is so far more effective beyond anything I could ask or think (Eph 3:20-note Col 1:29-note), that all the "glory" I once felt coming from the challenge to my self-effort is nothing but a pile of manure (that is the term he uses) (Php 3:8-note "rubbish" = that which is thrown to the dogs = the dregs, refuse, what is thrown away as worthless), compared with the glory of God at work in me (Php 2:13-note). It (The Old Covenant of Law) has lost all its splendor. I don't try to psych myself up in order to accomplish something for God. I know that even in my feeblest weakness God is able to work through me, and that is what I count on (2Co 3:5-note). What happens as a result is far more thrilling and adventurous than anything that ever happened before."

That is the Christian life. That is what the world is waiting to see in our day. We are all called to be ministers of the new covenant. (Ed: Functioning under the empowerment of the ministry of the Spirit and the ministry of righteousness) God is making us able, not ourselves (2Co 12:9-note, 2Co 12:10-note). If we understand that, life will never be the same again. You can count on that!

We thank you, heavenly Father, for this glimpse anew at what is true and real in the affairs of this world. We are made aware, Lord, of how many times we have been confused and blinded by the attitudes of the world around us which continually brainwash us to believe that it is something lying within us that is the secret of true power. Grant to us, Lord, that we may understand this truth, and believe it instead and, counting on you, discover your ability to change and heal and restore and forgive, manifest through us. We ask in your name, Amen. (Have you got What it Takes 2 Corinthians 3:1-11)

Remains (3306) (meno) means to abide and the present tense indicates the glory of the New Covenant is permanent. The glory of the New Covenant is never ending and does not need to be replaced, amended or updated because it fully accomplishes all of God's redemptive objectives.

Adam Clarke comments that the New Covenant...

As a great, universal, and permanent GOOD vastly excels a good that is small, partial, and transitory (Old Covenant)

A T Robertson comments...

This claim may be recommended to those who clamour for a new religion. Christianity is still alive and is not dying.