We sent - As discussed in verse 1 ("we") many commentaries explain this as a so-called "editorial we" but that may not be completely accurate. It is possible that Silvanus was involved in this decision to send Timothy.

F F Bruce for example notes that in the other situations where Paul sent Timothy (1Cor 4:17, Phil 2;19), he uses the first person singular so that

the natural inference from the plural epempsamen here is that Paul and Silvanus were jointly involved in sending Timothy back to Thessalonica (cf. Bengel: “ego et Silvanus”). In v 5, indeed, Paul takes personal responsibility for sending him.  This was fitting, since Timothy was Paul’s aide-de-camp: the initiative was presumably Paul’s and Silvanus agreed that Timothy should go. (Bruce, F F: 1 and 2 Thessalonians. Word Biblical Commentary. Dallas: Word, Incorporated. 1982 or Logos)

Sent (3992)(pempo) means to dispatch, send, thrust out. The verb is the general word for sending and means that Timothy was sent to do something. The fact that he was sent and not asked to go is consistent with the fact that his sending was under the authority of the apostle Paul.

Paul subsequently sent Timothy on other missions to the churches in...

Corinth...

For this reason I have sent to you Timothy, who is my beloved and faithful child in the Lord, and he will remind you of my ways which are in Christ, just as I teach everywhere in every church. (1 Cor 4:17)

Now if Timothy comes, see that he is with you without cause to be afraid; for he is doing the Lord's work, as I also am. Let no one therefore despise him. But send him on his way in peace, so that he may come to me; for I expect him with the brethren. (1Cor 16:10,11)

Philippi...

But I hope in the Lord Jesus to send Timothy to you shortly, so that I also may be encouraged when I learn of your condition. 20 For I have no one else of kindred spirit who will genuinely be concerned for your welfare. 21 For they all seek after their own interests, not those of Christ Jesus. 22 But you know of his proven worth that he served with me in the furtherance of the gospel like a child serving his father. 23 Therefore I hope to send him immediately, as soon as I see how things go with me; 24 and I trust in the Lord that I myself also shall be coming shortly. 25 But I thought it necessary to send to you Epaphroditus, my brother and fellow worker and fellow soldier, who is also your messenger and minister to my need (see note Phil 2:19; 20; 21; 22; 23; 24; 25)

Ephesus...

As I urged you upon my departure for Macedonia, remain on at Ephesus, in order that you may instruct certain men not to teach strange doctrines (1Ti 1.3).

Timothy's missionary trip to Thessalonica was the first recorded ministry that Timothy carried out on his own.

Gloag writes that the sending of Timothy...

This was a great act of self-sacrifice on the part of Paul; because to be without an assistant and fellow-labourer in the gospel in such a city as Athens, the very centre and strong hold of heathenism, full of temples and idols, must necessarily have brought upon him many discomforts; and yet his anxiety for the Thessalonians overcame all motives of personal convenience. (The Pulpit Commentary: New Testament; Old Testament; Ages Software  or Logos)

Brother (80) (adelphos from collative a = denoting unity + delphús = womb) is literally one born from same womb and so a male having the same father and mother as reference person.

Figuratively, adelphos here refers to a fellow believer in Christ. Timothy was Paul's spiritual child but here he refers to him as brother by virtue of the fact that they have both been born into the family of God by virtue of their faith in the Messiah.

Swete remarks

As the younger brother of their father in the faith, the Christians of Thessalonica would learn to regard him very highly.

God's fellow worker - That is an truth that the creature could be a fellow worker with the Creator and that is the divine design.

Our brother and God's fellow worker clearly indicate that Paul had not sent and unworthy substitute but a man who was fully capable of carrying out his mission. This small point is just another indication that Paul was deeply concerned about the spiritual welfare of his readers.

Note that here the KJV reads "Timotheus, our brother, and minister of God, and our fellow labourer in the gospel of Christ". It should be noted however that minister (diakonos) is not an official title and does not connote an ordained minister in the modern sense of the term but  instead designates one who renders a service of some kind to another. Diakonos speaks of the servant in relation to his work, stressing his activity of serving.

In regard to the Greek word diakonos Morris writes that...

Originally the word denoted the service of a table waiter, and from that it came to signify lowly service of any kind. It was often used by the early Christians to give expression to the service that they habitually were to render to both God and to man. Where a word like ‘slave,’ which is often used of Christians, puts the emphasis on the personal relation, this word draws attention to the act of service being rendered.”

Fellow worker (4904)(sunergos from sun = together with, speaks of an intimate relationship + érgon = work) means literally working together with and thus refers to a companion in work, a colleague, a co-laborer, a fellow laborer or fellow helper. 

Notice who Timothy is working with! It is as if God employs as His assistant, as it were (a fellow-worker with God)! Notice that in 1 Corinthians, Paul refers to all believers God’s fellow workers (1 Cor 3:9). Think of our familiar English word derived from sunergos -  Synergy which describes combined action or operation. It is interaction or cooperation of two or more organizations, substances, or other agents to produce a combined effect greater than the sum of their separate effects.

Timothy + God =
supernatural synergy!

In the NT, sunergos is used only of a co–worker or helper in the Christian work.  In each instance sunergos conveys the idea of an affectionate partnership and not merely that of an impersonal, official relationship. Paul twice specifically includes godly women among his fellow workers (Prisca or Priscilla Ro 16:3) and Euodia and Syntyche, two godly but quarreling members of the church at Philippi who had shared Paul’s “struggle in the cause of the gospel” (see note Philippians 4:3).

Thayer writes that sunergos "with a genitive of the person (refers to) one who labors with another in furthering the cause of Christ."

This word refers to someone who is a team player, who does not seek to run or control things on his own, nor serve for selfish or personal agendas.

Keathley says that sunergos...

refers to someone who is a team player. This is someone who does not seek to run or control things on his own, nor serve for selfish or personal agendas. There are two aspects of a team player in the body of Christ:

1.He or she is one who is a fellow worker with God. The head of the body is the Lord Jesus. The church belongs to Christ, not us. This means we are to get our orders and spiritual strength from the Lord and allow Him to work in and through us. We work as God’s fellow workers by submission to Him and by faith in His provision.

2.This also means we are to work together with our brethren in Christ as a part of God’s team. There is no such thing as a one-man team. We work to build up others and to help the body to function as a body. It means team work with each believer doing his share for the goals of the Head and the team.

In addition, sunergos brings out the fact that Timothy was a worker, which, in New Testament terms, means a minister or a servant of others. Selfish, self-centered agendas spoil our ability to not only be team players, but to work as servants. (1Thessalonians 3:1-13 )

This great word is used 13 times (predominantly by Paul) in the NT...

Romans 16:3 (note) Greet Prisca and Aquila, my fellow workers in Christ Jesus... 16:9 (note) Greet Urbanus, our fellow worker in Christ, and Stachys my beloved...16:21 (note) Timothy my fellow worker greets you, and so do Lucius and Jason and Sosipater, my kinsmen.

1 Corinthians 3:9 For we are God's fellow workers; you are God's field, God's building.

2 Corinthians 1:24 Not that we lord it over your faith, but are workers with you for your joy; for in your faith you are standing firm.

2 Corinthians 8:23 As for Titus, he is my partner and fellow worker among you; as for our brethren, they are messengers of the churches, a glory to Christ.

Philippians 2:25 (note)  But I thought it necessary to send to you Epaphroditus, my brother and fellow worker and fellow soldier, who is also your messenger and minister to my need;

Philippians 4:3 (note)  Indeed, true comrade, I ask you also to help these women who have shared my struggle in the cause of the gospel, together with Clement also, and the rest of my fellow workers, whose names are in the book of life.

Colossians 4:11 (note) and also Jesus who is called Justus; these are the only fellow workers for the kingdom of God who are from the circumcision; and they have proved to be an encouragement to me.

1Thessalonians 3:2 (note) and we sent Timothy, our brother and God's fellow worker in the gospel of Christ, to strengthen and encourage you as to your faith,

Philemon 1:1 Paul, a prisoner of Christ Jesus, and Timothy our brother, to Philemon our beloved brother and fellow worker...24 as do Mark, Aristarchus, Demas, Luke, my fellow workers.

3 John 1:8 Therefore we ought to support such men, that we may be fellow workers with the truth.

Gospel of Christ - In chapter 2 Paul referred to it as the Gospel of God three times emphasizing its origin and authority. Here the phrase Gospel of Christ emphasizes the One in and through Whom the good news was made available, the central "theme" of the Good News being the Christ. Paul is the only NT writer to use the specific phrase Gospel of Christ (click his 8 uses).

Hiebert offers a more technical explanation noting that...

The genitive "of Christ" may be interpreted as either a subjective or objective genitive. Under the former it denotes the gospel that is Christ's, which He has ordained to be preached; under the latter it points to the gospel that tells of Christ, the good news about Him as Savior. The latter seems to be the meaning here. (Hiebert, D. Edmond: 1 & 2 Thessalonians: BMH Book. 1996)

Gospel (2098)(euaggelion eú = good + aggéllo = proclaim, tell) originally referred to a reward for good news and later became the good news itself. The word euaggelion was in just as common use in the first century as our words good news today.  “Have you any good news for me today?” would have been a common question. In this secular use euaggelion described good news of any kind and prior to the writing of the New Testament, had no definite religious connotation in the ancient world until it was taken over by the "Cult of Caesar" which was the state religion and in which the emperor was worshipped as a god (see more discussion of this use below). The writers of the New Testament adapted the term as God's message of salvation for lost sinners.

TO STRENGTHEN AND ENCOURAGE YOU AS TO YOUR FAITH:  eis to sterixai humas kai parakalesai (AAN) huper tes pisteos humon: (1Thes 3:13; Acts 14:22,23; 16:5; Ephesians 6:22; Philippians 1:25)

Strengthen (4741)(sterizo from histemi = to stand) means to make firm or solid, to set fast, to fix firmly in a place, to establish (make firm or stable), to cause to be inwardly firm or committed, to strengthen. The basic idea is that of stabilizing something by providing a support or buttress (a projecting structure of masonry or wood for supporting or giving stability to a wall or building), so that it will not totter. The word implies fixedness.

Sterizo is employed frequently in those contexts where someone is in danger of falling in some way or another. Eg, in the Apocryphal book Sirach we read "When the rich person totters he is supported by friends".  Philo comments that those who are carried in different directions in their life are those who cannot be established. Diogenes Laertius refers to those people who are never firmly established in any dogma.

In the present verse sterizo is used metaphorically referring to their continual state of spiritual stability, especially in the face of potential apostasy or persecution

Vine feels that sterizo is derived from sterix, a prop (something that sustains or supports).

There is an illustrative use of sterizo in the Septuagint (LXX) translation of Exodus 17:12 (sterizo is used twice in this verse)...

But Moses' hands were heavy. Then they took a stone and put it under him, and he sat on it; and Aaron and Hur supported (sterizo) his hands, one on one side and one on the other. Thus his hands were steady (sterizo) until the sun set.

The following uses of sterizo demonstrate the various ways God uses to strengthen His saints and thus what and how Timothy was enabled to strengthen the faith of the saints in Thessalonica. These are the same "methods" believers today can utilize to strengthen the faith of their brethren, a need which is always present because every believer's faith is continually subject to testing. Have you ever been sent to strengthen another's faith? How would Timothy going to carry out Paul's charge to strengthen the faith of the saints at Thessalonica? Read on...

Believers are strengthened...

By fervent, Scripturally based prayers of the saints...

May the Lord cause you to increase and abound in love for one another, and for all men, just as we also do for you that He may establish (sterizo) your hearts unblamable in holiness before our God and Father at the coming of our Lord Jesus with all His saints. (see notes 1Thes 3:12; 13)

Now may our Lord Jesus Christ Himself and God our Father, who has loved us and given us eternal comfort and good hope by grace, comfort and strengthen (sterizo) your hearts in every good work and word. (2Th 2:16-17)

By looking and living for the Lord's return...

You too be patient  (makrothumeo - have a "long fuse" especially with difficult people - aorist imperative); strengthen (sterizo - aorist imperative Do it now - it's urgent!, active voice = you make the choice to do this) your hearts (the "control center" of your life), for the coming (parousia) of the Lord is at hand. (Jas 5:8)

By the God of all grace working through suffering...

And after you have suffered for a little while, the God of all grace, who called you to His eternal glory in Christ, will Himself perfect, confirm, strengthen and establish you. (1Pe 5:10-note)

By the truth of God's Word...

Therefore, I shall always be ready to remind you of these things, even though you already know them, and have been established (sterizo) in the truth which is present with you. (2Pe 1:12-note)

By the revealing of the mystery of the gospel...

Now to Him who is able to establish (sterizo) you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery which has been kept secret for long ages past (Ro 16:25-note);

By the strengthening ministered through His saints who come alongside...

(Peter) Simon, Simon, behold, Satan has demanded permission to sift you like wheat but I have prayed for you, that your faith may not fail; and you, when once you have turned again, strengthen (sterizo - aorist imperative conveys a sense of urgency. Do it effectively! When the opportunity presents itself, don't delay) your brothers." Lk 22:31,32

(Timothy) and we sent Timothy, our brother and God's fellow worker in the gospel of Christ, to strengthen (sterizo) and encourage you as to your faith,

(Paul) For I long to see you in order that I may impart some spiritual gift to you, that you may be established (sterizo) (Ro 1:11-note).

Jesus warns the church at Sardis

Wake up (gregoreuo as in 1Pe 5:8-note "be on the alert" - there was no time for indifference; they could not just go with the flow, they had to reverse it), and strengthen  (sterizo - aorist imperative - command to do this now - it is urgent)  the things that remain, which were about to die; for I have not found your deeds completed in the sight of My God. (Re 3:2-note)

Encourage (3870) (parakaleo [word study] from para = side of, alongside, beside + kaleo [ word study] = call) means literally to call one alongside, to call someone to oneself, to call for, to summon. Parakaleo can include the idea of giving help or aid but the primary sense in the NT is to urge someone to take some action, especially some ethical course of action. Sometimes the word means convey the idea of comfort, sometimes of exhortation but always at the root there is the idea of enabling a person to meet some difficult situation with confidence and with gallantry.

Kent Hughes illustrates the root idea of parakaleo "to come alongside and encourage" with the following example

I see this exemplified every time my church has a roller skating party, and the parents put their little ones on skates for the first time. Mom and Dad skate with their child, holding on to his or her hands, sometimes with the child’s feet on the ground and sometimes in the air. But all the time the parents are alongside encouraging....[exhortation] is a wonderful gift, and we are to place it at Christ’s feet and be willing to be worn out in its use.

Encourage one another - Study the "one anothers" - most positive, some negative

The English word "encourage" means “with heart.” To encourage in a sense is to give them new heart. Shallow sympathy makes people feel worse-true spiritual encouragement makes them feel better. It brings out the best in people.

In this usage of parakaleo the idea is to urge the Thessalonian saints to persevere and pursue a course of conduct specifically regarding their faith. Timothy came alongside them in order to encourage them to live according to sound doctrine which alone would assure that they stay firm and press on ahead in their faith. Do you know someone going through trials and afflictions? Have you come alongside them? Have you considered sending them an encouraging (parakaleo) note or email to let them know you are standing with them and praying for them? What effect might this have on their faith?

Ray Stedman writes that the saints at Thessalonica...

needed to be exhorted to steadiness, to not panic when things got tough. They should never forget that suffering and affliction could be surmounted. They had a resource to lean upon which they did not have before, so they did not have to fear. God would take them through everything and use it for their benefit. Paul had already laid the foundation for this when he was with them. (1Thessalonians 3:1-3:13)

In classic Greek parakaleo was used to describe the exhorting of troops who were about to go into battle. Sometimes parakaleo conveys the idea of comfort, sometimes of exhortation but always at the root there is the idea of enabling a person to meet some difficult situation with confidence and with gallantry.

One of the Greek historians uses parakaleo in a most interesting and suggestive way. There was a Greek regiment which had lost heart and was utterly dejected. The general sent a leader to talk to it to such purpose that courage was reborn and a body of dispirited men became fit again for heroic action. That is somewhat of the idea of parakaleo in Colossians 2:1-2...

For I want you to know how great a struggle (agon) I have on your behalf, and for those who are at Laodicea, and for all those who have not personally seen my face that their hearts may be encouraged (parakaleo - it could also be translated strengthen because the Colossians were beset by false teachers and needed strengthening as well as comfort - notice the phrase in their hearts signifies it is an inner strengthening brought about by truth not a list of do's and don'ts) having been knit together in love, and attaining to all the wealth that comes from the full assurance of understanding, resulting in a true knowledge of God's mystery, that is, Christ Himself (see notes Colossians 2:1; 2:2)

It was Paul’s prayer that the Churches at Colossae and Laodicea may be filled with that courage which can cope with any situation.

As to your faith - Instability and discouragement is usually the result of a faith that is weak, out of focus, or focused on the wrong object.

Faith (4102) (pistis) is synonymous with trust or belief and is the conviction of the truth of anything, but in Scripture usually speaks of belief  respecting man's relationship to God and divine things, generally with the included idea of trust and holy fervor born of faith and joined with it. As pistis relates to God, it is the conviction that God exists and is the Creator and Ruler of all things well as the Provider and Bestower of eternal salvation through Christ. As faith relates to Christ it represents a strong and welcome conviction or belief that Jesus is the Messiah, through Whom we obtain eternal salvation and entrance into the Kingdom of Heaven. Stated another way, eternal salvation comes only through belief in Jesus Christ and no other way.

SO THAT NO MAN MAY BE DISTURBED BY THESE AFFLICTIONS:  to medena sainesthai (PPN) en tais thlipsesin tautais: (Psalms 112:6; Acts 2:25; 20:24; 21:13; Romans 5:3; 1Corinthians 15:58; Ephesians 3:13; Philippians 1:28; Colossians 1:23; 2Thessalonians 1:4; 2Timothy 1:8; 1Peter 4:12, 13, 14; Revelation 2:10,13)

So that is more literally that but serves the same function of giving us the goal of Timothy's trip which was to establish and encourage (the Thessalonians) and to inform (Paul of their status).

No man (3367)(medeis from medé = and not, also not, neither, nor, not even + heís = one) means not even one, no one, no one whoever he may be. This phrase emphasizes that God intends for all believers to become spiritually strong and stable in the midst of the disturbing problems of life. Paul has God's heart that not a single believer's faith be set back by the afflictions.

It the heat of afflictions, it would be easy to imagine that God was displeased with you as a believer and that is why all the suffering was occurring. And it could have easily have caused the Thessalonian believers to be disturbed or unsettled in their faith.

Disturbed (shaken, unsettled, perturbed or deceived, deluded - see below)  (4525)(saino) means to wag, to move to and fro as dogs wag their tails in friendliness. As a dog wags his tail to allure, it gives rise to the meaning so to fascinate, beguile, flatter. To draw aside from the right path.

Chadwick mentions an occurrence of saino (actually "sainein") with the meaning “to perturb mentally” in a papyrus from Tura which reads...

all matters concerning the faith which have perturbed us have been examined

Saino pictures one who has become so emotionally disturbed as to be shaken in his/her beliefs and even to give up his/her beliefs. The present tense speaks of being continually disturbed. It's difficult to avoid being disturbed initially when a "surprise attack" occurs (as they will for all believers) but Paul's desire is that this "disturbance" doesn't continue to resonate.

Friberg summarizes the two possible meaning of saino...

(1) originally of dogs wag the tail, move the tail to and fro, fawn; figuratively, of persons fawn over, flatter; passive be deceived or deluded;

(2) figuratively and passive, as being carried away emotionally by circumstances be shaken, be disturbed, be unsettled; either meaning makes good sense in 1Thes 3:3 but ancient versions and Greek expositors prefer the second (interpretation).  (Friberg, T., Friberg, B., & Miller, N. F. Analytical Lexicon of the Greek New Testament. Baker Academic)

Hendricksen on the other hand favor the meaning of deceive or delude and thus renders this verse quite different from the NAS

to prevent anyone of you from being deceived in the midst of these afflictions.

In these afflictions - The Thessalonian saints’ sufferings at the hands of their fellow countrymen have been referred to in chapter 2...

For you, brethren, became imitators of the churches of God in Christ Jesus that are in Judea, for you also endured the same sufferings at the hands of your own countrymen, even as they did from the Jews (see note 1Thessalonians 2:14)

Paul's desire was that in spite of these sufferings the converts would stand firm and that the sufferings would even serve to deepen their faith.

Afflictions (2347) (thlipsis from thlibo = to crush, press together, squash, hem in, compress, squeeze in turn derived from thláo = to break) originally expressed sheer, physical pressure on a man. Medically thlipsis was used of the pulse (pressure). It is a pressing together as of grapes. It conveys the idea of being squeezed or placed under pressure or crushed beneath a weight. When, according to the ancient law of England, those who willfully refused to plead guilty, had heavy weights placed on their breasts, and were pressed and crushed to death, this was literally thlipsis. The iron cage was stenochoria. Thlipsis thus refers not to mild discomfort but to great difficulty.

Thlipsis - 45x in 43v - Matt 13:21; 24:9, 21, 29; Mark 4:17; 13:19, 24; John 16:21, 33; Acts 7:10f; 11:19; 14:22; 20:23; Rom 2:9; 5:3; 8:35; 12:12; 1 Cor 7:28; 2 Cor 1:4, 8; 2:4; 4:17; 6:4; 7:4; 8:2, 13; Eph 3:13; Phil 1:17; 4:14; Col 1:24; 1 Thess 1:6; 3:3, 7; 2 Thess 1:4, 6; Heb 10:33; Jas 1:27; Rev 1:9; 2:9f, 22; 7:14. NAS = affliction(14), afflictions(6), anguish(1), distress(2), persecution(1), tribulation(16), tribulations(4), trouble(1).

In chapter 1, Paul explained that

thlipsis is used as a technical theological term for the Great Tribulation (see note below) of the end times. Thlipsis is also used in a non-theological, figurative way to convey the idea of the great emotional and spiritual stress that can be caused by external or internal pressures. Of the fifty-five uses of this root (thlipsis and thlibo) in the NT, fifty-three are figurative and correspond closely to the Hebrew words tsarar and tsar." (Richards, L O: Expository Dictionary of Bible Words: Regency)

FOR YOU YOURSELVES KNOW THAT WE HAVE BEEN DESTINED FOR THIS: autoi gar oidate (2PRAI) hoti eis touto keimetha (1PPMI): (1Thes 5:9; Matthew 10:16, 17, 18; 24:9,10; Luke 21:12; John 15:19, 20, 21; 16:2,33; Acts 9:16; Acts 14:22; 20:23; 21:11,13; Romans 8:35, 36, 37; 1Corinthians 4:9; 2Timothy 3:11,12; 1Peter 2:21; 4:12)

For (gar) introduces the reason they should not be shaken or agitated.

You yourselves know - He reminds them that they had been taught by Paul, Silvanus and Timothy to expect suffering. In other words the sound doctrine which they knew was to be their foundation and anchor of their faith when the winds of affliction began to blow. Secondly, they were to remember that whatever afflictions were on their "appointment calendars" had been placed there or allowed to be there by their Sovereign Lord. And as writes in Romans believers can look at suffering from an eternal perspective...

The Spirit Himself bears witness with our spirit that we are children of God, and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him in order that we may also be glorified with Him. (See notes Romans 8:16; 8:17)

Suffering in this present life is evidence of the reality of one's faith as well as an earnest (a promise of what is to come) of the future glory. (see also 2Thes 1:4, 5, 6, 7, 8, 9, 10)

Know (1492) (eido) literally means perception by sight (perceive, see) as in Mt 2:2 where the wise men "saw His star". It is the verb that describes absolute, positive, beyond a chance of a doubt type of knowing something. The perfect tense speaks of the permanence of their knowing.  It refers to that quality of knowledge that is intuitive. It means to see with the mind’s eye, signifies a clear and purely mental perception. It describes one as having come to a perception or realization of something.

Fausset makes a good point writing that...

None but a religion from God would have held out such a trying prospect to those who should embrace it, and yet succeed in winning converts.

How did Paul expect them to remain undisturbed in the face of afflictions of other believers? See (1Th 3:2)...we all need someone to send us a "Timothy" from time to time to strengthen and encourage us as to our faith that we might hold fast, that we might run with endurance (He 12:1-note), that we might buffet our bodies (1Cor 9:24, 25, 26, 27-note), that we might lay hold of life indeed (1Ti 6:19), that we might fight the good fight, that we might run our race, that we might keep the faith (2Ti 4:7-note).

There is an eternity of difference between being destined for afflictions and not destined...for wrath, a contrast Paul brings out in the closing section of his letter...

God has not destined us for wrath, but for obtaining salvation through our Lord Jesus Christ (see note 1Thessalonians 5:9)

New believers (or at least those who profess belief in Christ) must be alerted to the truth that afflictions are guaranteed to come because of their faith in Jesus Christ, the One the unsaved world passionately, unremittingly hates! And so they will hate His blood covenant relatives! Therefore Jesus Himself models what we are to teach our disciples lest they are surprised and discouraged by the trials. The trials in part are used by God to separate the wheat (genuine believers) from those who have made only a profession (intellectual decision without repentance) of belief in Christ. In John Jesus explains why believers are destined for afflictions in this present world reminding His disciples that...

If you were of the world, the world would love its own; but because you are not of the world, but I chose you out of the world, therefore the world hates you. Remember the word that I said to you, 'A slave is not greater than his master.' If they persecuted Me, they will also persecute you; if they kept My word, they will keep yours also. But all these things they will do to you for My name's sake, because they do not know the One who sent Me. (John 15:19-21)

These things I have spoken to you (God's Truth is the sure stabilizing force in our continuous spiritual war with the terrorists -- the flesh, world and devil - so gird your loins with the truth - see note Eph 6:14), that in Me you may have peace (that which is at one, undivided). In the world you have tribulation (thlipsis), but take courage (present imperative = command to continually have confidence & firmness of purpose in face of danger/testing); I have overcome (Always of spiritual victory in the NT) the world. (John 16:33) (Spurgeon's devotional)

Comment: Note that the first 'have' (peace) is a possibility. {subjunctive mood}. The second have (affliction) is a certainty  {indicative mood}. Affliction is guaranteed for disciples but peace is not. Peace depends on our trusting Him because He is our peace. There is no Peace other than in Christ, our Life, Col 3:4. His peace is a product of abiding in Him, of listening, of obeying immediately, of confessing quickly and repenting from known sin.

To the saints at Philippi Paul wrote...

For to you it has been granted (a "gift of grace"!) for Christ's sake, not only to believe in Him, but also to suffer for His sake (Php 1:29-note)

In his last letter Paul alerts Timothy that...

indeed, all (no exceptions!) who desire to live godly in Christ Jesus will be persecuted. (2Ti 3:12-note)

J Vernon McGee explains that...

If you are a believer, you are not going to escape trouble. To accept Christ does not mean to take out an insurance policy against suffering. The fact of the matter is that you will have trouble after you become a child of God, even if you haven’t had any trouble before. He has never promised that we would miss the storm, but we will go through all the storms of life. What He does say very definitely and dogmatically is that He will go with us through the storms and that we will reach the harbor. Any boat which He is in will not go to the bottom of the Sea of Galilee but will reach the other side. You and I are in the process of going to the other side. (McGee, J V: Thru the Bible Commentary:  Thomas Nelson or Logos)

Richison reminds all believers that...

If you are in that cycle of your Christian life where everything is resulting in affliction, reverses or trouble, God knows how much you can bear and will not allow the pressure to become too great. The Lord is very careful how He measures out the pain that comes to your life. You can trust Him for that.

Commenting on the we in the phrase we have been destined for this, MacArthur notes that...

Actually it is not clear from verse 3 whether we refers primarily to Paul or the Thessalonians. Some assert that we denotes Paul, and the afflictions the sufferings to which he had been destined (cf. Acts 9:16). That interpretation sees Paul reminding the Thessalonians of his God-ordained difficulties so that they would not equate them with God’s disapproval of him or with nullification of His plans for him or even as evidence that he was not an apostle. Others see Paul’s statement as a reminder to the Thessalonians and all Christians that they should expect afflictions... The widest interpretation, which includes Paul and believers within the statement, may be best, since it truly applies to both. (Ed note: I agree). (MacArthur, John: 1 & 2 Thessalonians. Moody Press or Logos)

Destined (appointed) (2749) (keimai) means literally to be in a recumbent position, to lie down, to be laid down. The root meaning refers to lying down or reclining and came to be used of an official appointment and sometimes of destiny. In the military keimai was used of a special assignment, such as guard duty or defense of a strategic position - the soldier was placed (set) on duty.

Figuratively then, keimai means appointed (determined or decided upon) or destined as in this verse (and Lu 2:34 and Php 1:16-note where we see that Paul was divinely appointed for the defense of the gospel). Destined means  intended or chosen for a particular purpose or end. The idea is that God “sets (lays down)” something for a particular purpose. In context this usage of keimai affirms God's sovereignty and ultimate control of all things.

Note that destined is in the present tense which speaks of a continuing "appointment" (until we see Jesus face to face).  The passive voice implies that  God is the active agent (He certainly is the Agent in not destining believers for wrath in 1Thessalonians 5:9). Paul is not referring to the pagan idea of an impersonal fate nor to the Islamic idea of determinism. As discussed above, afflictions are the norm for believers in a fallen world.

In 1Thessalonians 3:3, Paul is using keimai figuratively to say in essence that appointments with trouble are already on our Day-timers®. He tells the believers at Thessalonica that he had told them this would happen. It’s part of God's program. Believers are to expect troubles and difficulties because they "are appointed to this." The encouragement and comfort of a fellow Christian (like Timothy's visit to the Thessalonians) during such trials can be an especially welcome source of strength to one's faith (strengthen and encourage - in preceding verse).

Vincent writes that keimai means...

primarily to be laid, and so to lie: hence to be set forth or promulgated, as the law is said to be laid down, and so, appointed or destined

Friberg adds that keimai...

literally, spatially and predominately as the result of being placed or set (means to) (a) lie in or on something (Lk 2:12); (b) of things being situated somewhere - stand, set (Mt 5:14); (c) of storage of goods - be laid up, be in store (Lk 12:19); (2) figuratively;  (a) of persons - be appointed, be set, be destined (Lk 2:34): (b) as a legal technical term - be laid down, exist, be valid (1Ti 1:9); (c) as being in a certain state or condition be, find oneself (in), lie (in the power of) (1John 5:19) (Friberg, T., Friberg, B., & Miller, N. F. Analytical Lexicon of the Greek New Testament. Baker Academic)

Jesus Himself had prophesied about Paul's coming afflictions (plural) declaring that...

he is a chosen instrument of Mine, to bear My name before the Gentiles and kings and the sons of Israel for I will show him how much he must suffer (why is he to suffer? read on...) for My name's sake. (Acts 9:15, 16)

AW Tozer was right when he said, Before God can use a person greatly, He must allow that person to be hurt deeply. 

God is not being cruel, but He knows that we cannot comfort others unless we have been comforted ourselves. So beloved, no matter what you might be experiencing you must remember the truth about God, that He is "the Father of mercies and God of all comfort  who comforts us in all our affliction so that we may be able to comfort those who are in any affliction with the comfort with which we ourselves are comforted by God." 2Cor 1:3, 4

Luke records that suffering is the destiny of all believers...

And after they had preached the gospel to that city and had made many disciples, they returned to Lystra and to Iconium and to Antioch, strengthening (episterizo - derived from  sterizo) the souls (their innermost being, that vital force which animates the body and shows itself in breathing) of the disciples, encouraging (parakaleo) them to continue in the faith, and saying, "Through many tribulations (plural of thlipsis) we must enter the kingdom of God." (Acts 14:21,22)

Comment: Observe how strengthening and encouraging saints going through spiritual battles is part of the SOP, standard operating procedure, for God's soldiers who would care of Christ's disciples. Note how Paul had sent Timothy to the Thessalonians prescribing this identical "antidote" for their afflictions in 1Thessalonians 3:2. We need to do likewise when we hear of a brother or sister in experiencing afflictions.

Keimai is used 7 times in the Septuagint (LXX) (Joshua 4:6; 2Sa 13:32; Ezra 6:1; Esther 3:13; Isa. 9:4; 30:33; Jer. 24:1) and 24 times in the NT...

Matthew 3:10 "And the axe is already laid at the root of the trees; every tree therefore that does not bear good fruit is cut down and thrown into the fire.

Matthew 5:14 (note) "You are the light of the world. A city set on a hill cannot be hidden." (Comment: Keimai means to be in a place frequently in sense of `being contained in' or `resting on' as in the present context of a city set on a hill)

Matthew 28:6 "He is not here, for He has risen, just as He said. Come, see the place where He was lying.

Luke 2:12 "And this will be a sign for you: you will find a baby wrapped in cloths, and lying in a manger."..16 And they came in haste and found their way to Mary and Joseph, and the baby as He lay in the manger...34 And Simeon blessed them, and said to Mary His mother, "Behold, this Child is appointed (set, destined) for the fall and rise of many in Israel, and for a sign to be opposed--

Luke 3:9 "And also the axe is already laid at the root of the trees; every tree therefore that does not bear good fruit is cut down and thrown into the fire."

Luke 12:19 'And I will say to my soul, "Soul, you have many goods laid up for many years to come; take your ease, eat, drink and be merry."'

Luke 23:53 And he took it down and wrapped it in a linen cloth, and laid Him in a tomb cut into the rock, where no one had ever lain.

John 2:6 Now there were six stone waterpots set there for the Jewish custom of purification, containing twenty or thirty gallons each.

John 19:29 A jar full of sour wine was standing there; so they put a sponge full of the sour wine upon a branch of hyssop, and brought it up to His mouth.

John 20:5 and stooping and looking in, he saw the linen wrappings lying there; but he did not go in. 6 Simon Peter therefore also came, following him, and entered the tomb; and he beheld the linen wrappings lying there, 7 and the face-cloth, which had been on His head, not lying with the linen wrappings, but rolled up in a place by itself....12 and she beheld two angels in white sitting, one at the head, and one at the feet, where the body of Jesus had been lying.

John 21:9 And so when they got out upon the land, they saw a charcoal fire already laid, and fish placed on it, and bread.

1 Corinthians 3:11 For no man can lay a foundation other than the one which is laid, which is Jesus Christ.

2 Corinthians 3:15 But to this day whenever Moses is read, a veil lies over their heart;

Philippians 1:16 (note) the latter do it out of love, knowing that I am appointed (I am put here or set here) for the defense of the gospel;

1Thessalonians 3:3 (note) so that no man may be disturbed by these afflictions; for you yourselves know that we have been destined for this (this is to be our lot).

1 Timothy 1:9 realizing the fact that law is not made for a righteous man, but for those who are lawless and rebellious, for the ungodly and sinners, for the unholy and profane, for those who kill their fathers or mothers, for murderers

1 John 5:19 We know that we are of God, and the whole world lies in the power of the evil one. (Vincent writes that in this verse keimai "is stronger than [esti] is, indicating the passive, unprogressive state in the sphere of Satan’s influence. “While we are, from God, implying a birth and a proceeding forth, and a change of state, the kosmos the world, all the rest of mankind, remains in the hand of the evil one” [Alford])

Revelation 4:2 (note) Immediately I was in the Spirit; and behold, a throne was standing in heaven, and One sitting on the throne.

Revelation 21:16 (note) And the city is laid out as a square, and its length is as great as the width; and he measured the city with the rod, fifteen hundred miles; its length and width and height are equal.

Richison sums up this section reminding all believers that...

God ordains us to affliction. When people become Christians, they receive a new kind of trouble. Affliction is God’s appointment for us. God places affliction strategically in our lives for our personal growth. This is God’s destiny for us that comes by His divine design. Affliction is God’s appointment for us. Trial is no accident. We can clearly see the folly of trying to evade persecutions. This was the appointed path of the Thessalonians. The word “appointed” here does not refer to past eternity but to present time. The Christian life being what it is and the godless world being what it is, makes afflictions and persecution certain. God says, “I have an appointment for you with affliction.” We make appointments regularly. This is an appointment that I would prefer not to keep!...Affliction is in the plan and will of God for the believer. Some of us might say, “What did I ever do to deserve this pain in my life. What did I do wrong?” It may be that you did not do anything wrong. This is just one of the by–products of being the child of the King. You say, “I don’t like these side–effects of Christianity.” A disciple is someone under discipline. God appoints trial into our lives so that we will become more disciplined in the things of God.  (Ref)

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In Our Daily Homily, F B Meyer writes the following note on 1Thessalonians 3:3...

WE all love the sunshine, but the Arabs have a proverb that "all sunshine makes the desert"; and it is a matter for common observation that the graces of Christian living are more often apparent in the case of those who have passed through great tribulation. God desires to get as rich crops as possible from the soil of our natures· There are certain plants of the Christian life, such as meekness, gentleness, kindness, humility, which cannot come to perfection if the sun of prosperity always shines.

We often shrank from the lessons set us at school, and looked out of the windows, longing for the hour of release. But now how thankful we are for the tutors and governors, appointed by our parents, who kept us steadily at our tasks. We feel almost kindly to the schoolmaster or mistress that we dreaded. And, similarly, one day we shall be glad for those hard lessons acquired from the horn-book of pain. "We have had fathers of our flesh to chasten us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, who chastens for our profit, and live?"