FOR SINCE THE CREATION OF THE WORLD HIS INVISIBLE ATTRIBUTES: ta gar aorata autou apo ktiseos kosmou: (John 1:18; Colossians 1:15; 1Ti 1:17; 6:16; Heb 11:27) (Ro 1:19; Deut 4:19; Job 31:26, 27, 28; Psalms 8:3; 33:6, 7, 8, 9; 104:5,31; 119:90; 139:13; Psalms 148:8, 9, 10, 11, 12; Mt 5:45)

See Sermons by C H Spurgeon -

Romans 1:20-21 Inexcusable Irreverence and Ingratitude
Romans 1:20-21  Knowledge, Worship, Gratitude

For (1063)  (gar) is a subordinating conjunction which Introduces the explanation of how God made a knowledge of Him evident to all mankind.

Hodge writes that...

This verse is a confirmation and amplification of the preceding, inasmuch as it proves that God does manifest Himself to men, shows how this manifestation is made, and draws the inference that men are, in virtue of this revelation, inexcusable for their impiety. The argument is, God has manifested the knowledge of Himself to men, for the invisible things of Him, that is, his eternal power and Godhead, are, since the creation, clearly seen, being understood by His works; they are therefore without excuse.— Commentary on the Epistle to the Romans

Creation (2937) (ktisis) refers to bringing something into existence which has not existed before.

Here are the 19 NT uses of ktisis -- Mark. 10:6; 13:19; 16:15; Rom. 1:20, 25; 8:19, 20, 21, 39; 2 Co. 5:17; Gal. 6:15; Col. 1:15, 23; Heb. 4:13; 9:11; 1 Pet. 2:13; 2 Pet. 3:4; Rev. 3:14. The NAS translate ktisis as created thing(1), creation(14), creature(3), institution(1).

World (2889) (kosmos) describes an orderly arrangement and here refers to the order of the universe. The Greeks used kosmos to refer to the universe from the fact of its perfect arrangement. It was used in this case as opposed to the Greek word chaos which was used by the Greeks of the first state of existence, the rude, unformed mass out of which the universe was made. Thus the Greeks believed that the original state of the universe was one of chaos which is in line with the theory of evolution and the so-called "big bang" theory, which has been "exploded" by Creationists and believing scientists, even though this theory is still held to tenaciously by the majority of the scientific world.

Invisible (517) (aoratos from a = without + horáo = see) is that which cannot be seen with physical eyes. That which cannot be seen or is imperceptible by the sight.

Hodge explains that...

By the invisible things of God Theodoret says we are to understand creation, providence, and the divine judgments; Theophylact understands them to refer to his goodness, wisdom, power, and majesty. Between these interpretations the moderns are divided. The great majority prefer the latter, which is obviously the better suited to the context, because the works of God are expressed afterwards by poiemata and because the invisible things are those which are manifested by his works, and are explained by the terms “power and Godhead.” — Commentary on the Epistle to the Romans

Here are the five NT uses of aoratos -- Ro 1:20; Col. 1:15, 16; 1Ti 1:17; Heb 11:27. There are 2 uses in the non-apocryphal Septuagint - Ge 1:2; Is 45:3.

ISBE article on Invisible...

This term is used as an attribute of God in every biblical occurrence except Col. 1:16, where it refers to ranks of unseen angels and other spiritual powers. That no one had seen God at Sinai is stated in the OT (Ex 34:20; Deut. 4:12), and, in spite of God’s special self-disclosure to Moses (Ex. 33:18, 19, 20, 21, 22, 23; Nu. 14:14), it became axiomatic in Judaism that no one had seen or could see God in this present age (SB, II, 362f; cf. Mt. 5:8). The influence of this concept is reflected in the Johannine writings, with their emphasis that “no one has seen God” (Jn 1:18; 5:37; 6:46; 14:9; 1Jn. 4:12), and in the Pauline tradition as well (Rom. 1:20; Col. 1:15, 16; 1Ti 1:17; 3:16). The use of aóratos in the context of a doxology (1Ti 1:17) and in an adjectival clause with the pronoun “who” (“who is invisible”; Heb 11:27) shows that “invisible” was one of the ascriptions to God used in early Christian liturgy  (Bromiley, G. W. The International Standard Bible Encyclopedia, Revised. Wm. B. Eerdmans)

Visible Nature
speaks of
nature's invisible God.

In (Psalm 19:1-6) David writes that...

1 The heavens are telling (LXX = set out in detail) of the glory of God;
   And their expanse is declaring (LXX = proclaiming openly) the work of His hands.
2 Day to day pours forth speech,
   And night to night reveals knowledge.
3 There is no speech, nor are there words;
   Their voice is not heard.
4 Their line has gone out through all the earth,
   And their utterances to the end of the world.
   In them He has placed a tent for the sun,
5 Which is as a bridegroom coming out of his chamber;
   It rejoices as a strong man to run his course.
6 Its rising is from one end of the heavens,
   And its circuit to the other end of them;
   And there is nothing hidden from its heat.

Note the repeated emphasis in Psalm 19 - "telling", "declaring", "pours forth speech", "reveals knowledge", "utterances". And the extent of this clear proclamation - "all the earth", "end of the world". Observe that in the opening verse of Psalm 19, David writes that "The heavens are telling (LXX translates the Hebrew word for "telling" with the verb anagello in the present tense  = the heavens are continuously announcing in detail) of the glory of God"

In short anyone who has ever looked into the glittering night sky or at a radiant red-orange sunset has no excuse to not believe in God!  But humanity today prefers Hollywood or computer video games to seeing the "things" of the glorious God in the heavens. Beloved, when was the last time you walked outside and gazed at the moon and stars made by our Creator?

Newell quips that...

“The heavens declare the glory of God.” But humanity today prefers Hollywood’s “sound-pictures” to seeing the “things” of the glorious God in the heavens,—beholding His works, and hearing their speech. How long since you have gone out and gazed at moon and stars, made by the blessed God, travelling in such quiet glory, beauty, power, and order? Men know, if they care to know, that an infinite Majesty made and controls this. Romans Verse-by-Verse

Did you observe the paradox in Romans 1:20? invisible things which are visible! This state of things has been true since the creation of the universe. The eternal power and Godhead of the Creator have been since that time and are now understood by the things that have been made, namely, the material creation. Man, reasoning upon the basis of the law of cause and effect, which law requires an adequate cause for every effect, is forced to the conclusion that such a tremendous effect as the universe, demands a Being of eternal power and of divine attributes.

Charles Hodge wrote that God...

...has never left himself without a witness. His existence and perfections have ever been so manifested that His rational creatures are bound to acknowledge and worship Him as the true and only God” (Hodge, C: Commentary on the Epistle to the Romans Grand Rapids: Eerdmans)

ALL CREATION IS
AN OUTSTRETCHED FINGER
POINTING TO GOD!

The Heavens reveal the power of God
To everyone living on earth;
But then the good news of the gospel must come
From those who've experienced new birth. -- Sper

HIS ETERNAL POWER: e te aidios autou dunamis: (Ro 16:26; Ge 21:33; Deut 33:27; Ps 90:2; Isaiah 9:6; 26:4; 40:26; 1Ti 1:17; Heb 9:14)

Eternal (126) (aidios from aeí = ever, always) means everlasting, having infinite duration, lasting or enduring forever,  existing or continuing without end.

See related resource: God's Attribute - Eternal

Eternal in this context speaks of God's power which has no beginning and no end, even as God Himself is without beginning or end! Although aidios is not used in the following verse, the idea is the same...

Deuteronomy 33:27 The eternal God is a dwelling place, and underneath are the everlasting arms (cp "eternal power"); and He drove out the enemy from before you, and said, 'Destroy!' (cp Is 9:6 Eternal or Everlasting Father)

Aidos is used elsewhere in the New Testament only in Jude 1:6 (twice in the apocrypha - 4 Ma 10:15; Wis. 7:26).

Jude 1:6 And angels who did not keep their own domain, but abandoned their proper abode, He has kept in eternal bonds under darkness for the judgment of the great day.

Both the unchangeableness and omnipotence of God (see discussion of His omnipotence) are here in view, as exhibited in creation. The Creator, who made all that we see around us and constantly sustains it, must be a being of awesome power.

ISBE article on Eternal...

ETERNAL - e-tur'-nal (`olam; aionios, from aion): The word "eternal" is of very varying import, both in the Scriptures and out of them.

1. `Olam:

In the Old Testament, the Hebrew word `olam is used for "eternity," sometimes in the sense of unlimited duration, sometimes in the sense of a cycle or an age, and sometimes, in later Hebrew, in the signification of world. The Hebrew `olam has, for its proper New Testament equivalent, aion, as signifying either time of particular duration, or the unending duration of time in general. Only, the Hebrew term primarily signified unlimited time, and only in a secondary sense represented a definite or specific period. Both the Hebrew and the Greek terms signify the world itself, as it moves in time.

2. Aion, Aionios:

In the New Testament, aion and aionios are often used with the meaning "eternal," in the predominant sense of futurity. The word aion primarily signifies time, in the sense of age or generation; it also comes to denote all that exists under time-conditions; and, finally, superimposed upon the temporal is an ethical use, relative to the world's course. Thus aion may be said to mean the subtle informing spirit of the world or cosmos--the totality of things. By Plato, in his Timaeus, aion was used of the eternal Being, whose counterpart, in the sense-world, is Time. To Aristotle, in speaking of the world, aion is the ultimate principle which, in itself, sums up all existence.. In the New Testament, aion is found combined with prepositions in nearly three score and ten instances, where the idea of unlimited duration appears to be meant. This is the usual method of expressing eternity in the Septuagint also. The aionios of 2 Cor 4:18 must be eternal, in a temporal use or reference, else the antithesis would be gone.

3. Aidios:

In Ro 1:20 the word aidios is used of Divine action and rendered in the King James Version "eternal" (the Revised Version (British and American) "everlasting"), the only other place in the New Testament where the word occurs being Jude 1:6, where the rendering is "everlasting," which accords with classical usage. But the presence of the idea of eternal in these passages does not impair the fact that aion and aionios are, in their natural and obvious connotation, the usual New Testament words for expressing the idea of eternal, and this holds strikingly true of the Septuagint usage also. For, from the idea of aeonian life, there is no reason to suppose the notion of duration excluded. The word aionios is sometimes used in the futurist signification, but often also, in the New Testament, it is concerned rather with the quality, than with the quantity or duration, of life. By the continual attachment of aionios to life, in this conception of the spiritual or Divine life in man, the aeonian conception was saved from becoming sterile.

4. Enlargement of Idea:

In the use of aion and aionios there is evidenced a certain enlarging or advancing import till they come so to express the high and complex fact of the Divine life in man. In Greek, aiones signifies ages, or periods or dispensations. The aiones of Heb 1:2, and Heb 11:3, is, however, to be taken as used in the concrete sense of "the worlds," and not "the ages," the world so taken meaning the totality of things in their course or flow.

5. Eternal Life:

Our Lord decisively set the element of time in abeyance, and took His stand upon the fact and quality of life--life endless by its own nature. Of that eternal life He is Himself the guarantee--"Because I live, ye shall live also" (Jn 14:19). Therefore said Augustine, "Join thyself to the eternal God, and thou wilt be eternal." (Phrase "eternal life" in NAS - Mt 19:16, 29; 25:46; Mark. 10:17, 30; Lk 10:25; 18:18, 30; Jn 3:15, 16, 36; 4:14; 5:24, 39; 6:27, 40, 47, 54, 68; 10:28; 12:50; 17:2, 3; Ac 13:46, 48; Ro 2:7; 5:21; 6:22, 23; Gal. 6:8; 1Ti 1:16; 6:12; Titus 1:2; 3:7; 1Jn. 1:2; 2:25; 3:15; 5:11, 13, 20; Jude 1:21)

Power (1411) (dunamis - words derived from the stem duna— all have the basic meaning of “being able,” of “capacity” in virtue of an ability) refers to inherent ability, the power or ability to carry out some function, the potential for functioning in some way, the power residing in a thing by virtue of its nature. It conveys the idea of effective, productive energy, rather than that which is raw and unbridled. God's dunamis has always existed.

From a paper by B B Warfield in Jan,1889 on Darwin's arguments against Christianity:

The history of the drift by which Mr. Darwin was separated from faith in a divine order in the world, divides itself into two well-marked periods. The first of these, which was completed at about the time when he reached his fortieth year, ends with the loss of his Christianity. During the second, which extended over the remainder of his life, he struggled, with varying fortunes, but ever more and more hopelessly, to retain his standing at least as a theist. At the end of the first he no longer believed that God had ever spoken to men in his Word; at the end of the second he more than doubted whether the faintest whisper of his voice could be distinguished in his works. He was never prepared dogmatically to deny His existence; but search as he might he could not find Him, and he could only say that if He existed He was, verily, a God that hides Himself.

For an interesting article on whether Darwin's had a so called deathbed conversion (click here)

AND DIVINE NATURE: kai theiotes: (Acts 17:29; Colossians 2:9)

Divine nature (2305) (theiotes from theos = God) usually refers to performance that one might properly associate with a divinity. Theiotes emphasizes the divine nature and properties or the whole of that which goes to make up our idea of God. In a sense theiotes is a good summary term for the attributes which constitute deity, signifying  the sum-total of the divine attributes.

Theiotes describes the quality of theos and corresponds more to Latin divinitas from divus, divine. It refers to the quality or characteristics pertaining to deity and thus refers to divinity, divine nature or divineness.

Theiotes could be translated divine majesty and is seen supremely in Jesus Who uniquely bears the divine image (cf. 2Cor. 4:4; see Heb 1:3-note). He is God’s full revelation in human form (see Col 1:19-note; Col 2:9-note). The wonderful truth of the gospel is that fallen mankind, through faith in Christ, will share Christlikeness (cf. Heb 12:10-note; 1Jn 3:2). The image of God in humanity (cf. Ge 1:26,27) has been restored!

Theotes is the Divine Personality and theiotes the Divine Nature and properties

Wuest writes that...

The Greek word translated “Godhead” needs some study. It is theiotēs. We will compare it to theotēs (also translated “Godhead” a.v.) in order to bring out its meaning more clearly. Theotēs is used by Paul in Colossians 2:9 (see note) where he speaks of the fact that in our Lord “there is permanently at home all the fulness of absolute deity bodily” (in His incarnate state).

Trench comments,

St. Paul is declaring that in the Son there dwells all the fulness of absolute Godhead; they were no mere rays of divine glory which gilded Him, lighting up His Person for a season and with a splendor not His own; but He was, and is, absolute and perfect God.”

Commenting on the use of theiotēs in Romans 1:20, he says,

St. Paul is declaring how much of God may be known from the revelation of Himself which He has made in nature, from those vestiges of Himself which men may everywhere trace in the world around them. Yet it is not the personal God whom any man may learn to know by these aids: He can be known only by the revelation of Himself in His Son; but only His divine attributes, His majesty and glory … it is not to be doubted that St. Paul uses this vaguer, more abstract, and personal word, just because he would affirm that men may know God’s power and majesty, His divine power (2Peter 1:3) from His works; but would not imply that they may know Himself from these, or anything short of the revelation of His eternal Word. Motives not dissimilar induce him to use to theion rather than ho theos in addressing the Athenians on Mars Hill (Acts 17:29).”

Vincent says,

Godhead expresses deity (theotēs). Theiotēs is godhood, not godhead. It signifies the sum-total of the divine attributes.

Thus, through the light of the created universe, unsaved man recognizes the fact that there is a supreme Being who created it, who has eternal power and divine attributes, a Being to whom worship and obedience are due. This is the truth which unsaved man is repressing. Herein lies the just condemnation of the entire race, since it has not lived up to the light which it has. This, Paul says, renders man without excuse. (Wuest, K. S. Wuest's Word Studies from the Greek New Testament: Eerdmans or Logos)

Vine notes that theiotes is

used here only in the New Testament, is associated in meaning with theotes, Godhead, which is used only in Colossians 2:9 (see note). There is, however, a certain distinction in meaning and accordingly the former is here translated “divinity” and the latter “godhead.” The difference in the words is appropriate to the respective passages. Here Paul is speaking of the revelation which God has given in nature of His divine attributes. Man can thereby know certain facts about Him, such as His divinity, but cannot know God personally. Such knowledge can come only through the Son of God (cp. Jn 17:25 with Jn 1:18). In Colossians 2:9 (see note) Paul is speaking of the absolute Godhead of Christ, the fullness of which dwells in Him, and not of an external revelation of His divine attributes. Hence the suitability of theotes, d