BUT WE DO NOT WANT YOU TO BE UNINFORMED BRETHREN ABOUT THOSE WHO ARE ASLEEP: Ou thelomen (1PPAI) de humas agnoein, (PAN) adelphoi  peri ton koimomenon, (PPPMPG): (Romans 1:13; 1 Corinthians 10:1; 12:1; 2 Corinthians 1:8; 2 Peter 3:8) (1 Thes 4:15; 5:10; 1 Kings 1:21; 2:10; Daniel 12:2; Matthew 27:52; Luke 8:52,53; John 11:11-13; Acts 7:60; 13:36; 1 Corinthians 15:6,18; 2 Peter 3:4)

1 Thessalonians 4:13-18 is the classic New Testament passage on the rapture of the church. The Thessalonians’ ignorance about the Rapture caused them to grieve. It was to give them hope and to comfort them that Paul discussed that momentous event.

Frame writes that...

Since Paul’s departure, one or more of the Thessalonian Christians had died. The brethren were in grief not because they did not believe in the resurrection of the saints, but because they feared that their dead would not have the same advantages as the survivors when the Lord came. Their perplexity was due not simply to the Gentile difficulty of apprehending the meaning of resurrection, but also to the fact that Paul had not when he was with them discussed explicitly the problem of the relation of survivors to dead at the Parousia. (Frame, J. E.. A Critical and Exegetical Commentary on the Epistles of St. Paul to the Thessalonians. New York: C. Scribner's Sons. 1912)

Spurgeon wrote...

Tears are permitted to us, but they must glisten in the light of faith and hope. Jesus wept, but Jesus never repined (to be fretful or low-spirited through discontent). We, too, may weep, but not as those who are without hope, nor yet as though forgetful that there is greater cause for joy than for sorrow in the departure of our brethren

But (de) introduces a transition to a new subject.

Richison comments that...

The restlessness of disorderly believers (1 Thessalonians 4:11–12) was, in part, caused by an incomplete understanding of the Rapture of the church. They rightly understood that the coming of Christ was imminent, that is, no sign needed fulfillment before He came again. However, they had not considered the possibility that some of their friends would die before it occurred. They, therefore, plunged into deep grief. Doubts filled their minds as to the status of these prematurely deceased believers. (1Thessalonians 4:13; 13b; 13c; 4:14; 14b)

Ray Stedman says that to help understand this account we must remember that...

the Thessalonians had clearly been expecting the return of Jesus before any of them died. This was a moment-by-moment expectancy in the early church. First century Christians never entertained the thought that death would occur for them. They believed the Lord was coming within days, or weeks at the most. In the first chapter of this letter Paul commends the Thessalonians for "waiting for God's Son from heaven," {cf, note 1Thessalonians 1:10}. That is what they were looking for. (See his sermon Comfort at the Grave)

Not (3756) (ou) means absolutely "never"!

The Pauline phrase "not want you to be ignorant" although negative in form is positive in meaning. Milligan adds that this phrase is commonly used by Paul to introduce a new, important topic (eg, see  cf. Romans 1:13 [note], 11:25 [note - God's plan for Israel], 1 Cor 10:1, 12:1 [spiritual gifts], 2 Cor 1:8 [afflictions and comfort]).

Want (2309) (thélo) speaks of a desire that comes from one’s emotions and represents an active decision of the will (implying volition and purpose). Thelo is a conscious willing and denotes a more active resolution urging one on to action. 

Vincent commenting on the phrase I would not have you to be ignorant writes that the introductory phrase

we would not, etc. (was) a formula often used by Paul to call special attention to what he is about to say. See notes Romans 1:13; 11:25; 1Cor 10:1, etc.

Richison comments that...

This phrase, expressing that Paul does not want them to be ignorant is a formula customarily used to discuss difficult problems and correct false ideas (Romans 1:13 [note], 11:25 [note]; 1 Corinthians 10:1; 12:1). Usually, whenever the Bible warns us that we are ignorant about something, it is warranted. The topic of Christians dying is so important to the Thessalonians that it requires an explanation from the apostle Paul. The only way we can know about the afterlife is through the revelation found in the Bible. If we have adequate knowledge of what the Bible teaches about this subject, then it will dispel excessive grief in our souls. We can only resolve our ignorance by reading the Bible. We will rid ourselves of excessive grief by eliminating our ignorance about the future. The Thessalonians were clearly looking for the Lord’s return at the rapture, but they did not know the state of their dead loved ones until that point. They thought that those who died would miss the Rapture. (1Thessalonians 4:13; 13b; 13c; 4:14; 14b)

Uniformed (50) (agnoeo from a = not + noéo = perceive with the mind, to understand) (See study of noun agnoia) means to be ignorant, to not have information about, to not know, to be unaware of.

Ignorance is not bliss in regard to what happens when a believer dies!

MacArthur explains that...

Their concern for those who had died shows that the Thessalonians believed the return of Christ was imminent and could happen in their lifetime. Otherwise, there would have been no reason for their concern. The Thessalonians’ fear that their fellow believers who had died might miss the Rapture also implies that they believed in a pretribulational Rapture. If the Rapture precedes the Tribulation, they might have wondered when believers who died would receive their resurrection bodies. But there would have been no such confusion if the Rapture follows the Tribulation; all believers would then receive their resurrection bodies at the same time. Further, if they had been taught that they would go through the Tribulation, they would not have grieved for those who died, but rather would have been glad to see them spared from that horrible time. (MacArthur, John: 1 & 2 Thessalonians. Moody Press or Logos)

Brethren (80) (adelphos from collative a = copulative prefix {joining together coordinate words} or connective particle serving to join or unite + delphús = womb) is literally one born from same womb and literally identifies a male having the same father and mother. Figuratively as used throughout this epistle adelphos refers to a close associate of a group of persons having well-defined membership, specifically identifying fellow believers in Christ united by the bond of affection. In chapter 4 Paul repeatedly (see notes 1Thes 4:1; 4:6; 4:9) appeals to the relationship the Thessalonians have with Paul in Christ. In short, the truth that Paul is about to reveal is strictly for those who know Christ as their Savior and Lord.

About (4012) (peri) means around and here conveys the sense of concerning or regarding.

Are asleep (2837) (koimao related to keímai = to lie outstretched, to lie down) literally refers to normal sleep but is used figuratively in the present context referring to those who are dead and specifically those who are "dead in Christ" ("those also who have fallen asleep in Christ")

Robertson comments that the...

Present tense (of koimao) gives idea of repetition, from time to time fall asleep. Greeks and Romans used this figure of sleep for death

In other words Paul is referring to those are continually falling asleep as a regular course of life in the church. The believers in Thessalonica had grown increasingly concerned as their fellow believers continued to die.

Here are other uses of koimao which help us understand that it was a "euphemistic" reference to death in certain contexts..

(After Stephen had been stoned Luke records) And (Stephen) falling on his knees, he cried out with a loud voice, "Lord, do not hold this sin against them!" And having said this, he fell asleep (koimao) (Acts 7:60)

For David, after he had served the purpose of God in his own generation, fell asleep, and was laid among his fathers, and underwent decay (Acts 13:36)

1 Corinthians 7:39 A wife is bound as long as her husband lives; but if her husband is dead (koimao), she is free to be married to whom she wishes, only in the Lord.

1 Corinthians 11:30 For this reason many among you are weak and sick, and a number sleep (have died)

1 Corinthians 15:6 After that He appeared to more than five hundred brethren at one time, most of whom remain until now, but some have fallen asleep...18 Then (if Christ was not resurrected) those also who have fallen asleep in Christ have perished...20 But now Christ has been raised from the dead, the first fruits (see Christ the First Fruits) of those who are asleep...51 Behold, I tell you a mystery; we shall not all sleep, (not all believers will die - specifically those who alive when the Lord returns will not die a physical death) but we shall all be changed,

2Peter 3:4 (note) and saying, "Where is the promise of His coming? For ever since the fathers fell asleep, all continues just as it was from the beginning of creation.

Hiebert notes that sleep was a well known euphemism for death and...

did not originate with Christianity. It was a common metaphor among the Jews and was current even among pagans. The figure was apparently suggested by the stillness of the body and its apparent restfulness upon death; it was used even where there was no hope of resurrection. Having been used by the Master Himself (Mark 5:39; John 11:11), Christians readily accepted the term as a witness to their faith concerning death. The figure is not distinctively Christian, yet, as Morris well remarks, it is "much more at home in a Christian context than elsewhere."  (Hiebert, D. Edmond: 1 & 2 Thessalonians: BMH Book. 1996)

Sleep was used as a euphemism for death in Homer’s poem The Iliad, when at the death of a young warrior the lament sounds forth...

So there he fell, and slept a sleep of bronze, unhappy youth, far from his wedded wife. (Iliad 11.241-243)

The Roman poet Catullus appeals for the devotion of his lover by reminding her that life is short and that an unending night follows

Suns may set and rise again. For us, when the short light has once set, remains to be slept the sleep of one unbroken night. (Poems 5)

Jacob as he anticipates his own death makes this request of Joseph...

When I lie down with my ancestors, carry me out of Egypt and bury me in their burial place. (Gen. 47:30)

The death of King David is described as sleep...

Then David slept with his ancestors (1 Kings 2:10)

Stedman adds that koimao...

is never used in the New Testament of anyone but believers. It never says of a non-believer when he died that he "fell asleep." There is a wonderful lesson in that. It shows that death, for the believer, is nothing more than sleep. When your loved ones fall asleep you do not run to the phone and dial 911 for emergency service for them. You know that they are quietly resting, that they will awaken again, and that you will have contact with them again soon. That is why the New Testament regards the death of believers as nothing but sleep. (See his sermon Comfort at the Grave)

Koimao is the root of our English word cemetery (koimeterion) which was adopted by the early Christians as their optimistic name for the graveyard, being used this way first in Christian burials in the Roman Catacombs. The Koimeterion literally meant "a sleeping place" and was used by Greeks to describe a place of rest, a room for sleeping (bedroom), or a rest house for strangers. Koimeterion was also a synonym for a dormitory or place where people sleep.

Death for a Christian is considered merely being asleep. Jesus even had to explain this great truth to His disciples.

This He said, and after that He said to them, "Our friend Lazarus has fallen asleep (koimao); but I go, that I may awaken him out of sleep." The disciples therefore said to Him, "Lord, if he has fallen asleep (koimao), he will recover." Now Jesus had spoken of his death, but they thought that He was speaking of literal sleep. Then Jesus therefore said to them plainly, "Lazarus is dead, (John 11:11-14)

The sleep, however, applies only to the body, for the soul and spirit are with the Lord

we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord. (2 Corinthians 5:8).

The metaphorical use of the word sleep is appropriate because of the similarity in appearance between a sleeping body and a dead body, restfulness and peace at least outwardly characterizing both states.

Just as the sleeper does not cease to exist while his body "sleeps", so the dead person continues to exist despite his absence from the region in which those who remain can communicate with him. In addition, just as normal sleep is temporary, so too is the death of the body. And thus even as sleep has its time of waking, death will have its awakening which we call the resurrection. There is a resurrection of believers (the "first resurrection") and of non-believers ("second resurrection" which is the preface to the "second death" or eternal separation from God in the Lake of fire). (See discussion of The "First" and "Second" Resurrection)

There is a false teaching known as "soul sleep" that says that souls of the dead are in a state of unconscious existence. They claim that after a long period, God will awaken the soul. This is not the teaching of Scripture. In the NT "sleep" in the context of death applies only to the body and never to the soul.

Hiebert adds that...

The theory of soul sleep is inconsistent with Paul's assertion in 1Thessalonians 5:10 (see note) that God's purpose for us is that whether we live or die we should live together with Christ. (Ibid)

MacArthur explains why "soul sleep" is a false teaching writing that...

 In 2 Corinthians 5:8 Paul wrote that he “prefer[red] rather to be absent from the body and to be at home with the Lord,” while in Philippians 1:23 (note) he expressed his “desire to depart and be with Christ, for that is very much better.”

Those statements teach that believers go consciously into the Lord’s presence at death, for how could unconsciousness be “very much better” than conscious communion with Jesus Christ in this life?

Jesus promised the repentant thief on the cross, “Truly I say to you, today you shall be with Me in Paradise [heaven; cf. 2 Cor. 12:4; Revelation 2:7{note}]” (Luke 23:43).

Moses’ and Elijah’s souls were not asleep, since they appeared with Jesus at the Transfiguration (Mt 17:3), nor are those of the Tribulation martyrs in Revelation 6:9-11 (see notes Revelation 6:9;  6:10; 6:11), who will be awake and able to speak to God. After death the redeemed go consciously into the presence of the Lord, while the unsaved go into conscious punishment (Ed note: Read this passage about a "certain rich man" and a "poor man named Lazarus" who both die and end up in different "compartments" of Hades, the temporary abode of the dead. - Luke 16:19-31). (MacArthur, John: 1 & 2 Thessalonians. Moody Press or Logos)

Vincent comments that...

in Christian speech and thought, as the doctrine of the resurrection (1Corinthians 15:1-58) struck its roots deeper, the word dead, with its hopeless finality, gave place to the more gracious and hopeful word sleep. The pagan burying-place carried in its name no suggestion of hope or comfort. It was a burying-place, a hiding-place, a monumentum, a mere memorial of something gone; a columbarium, or dove-cot, with its little pigeon-holes for cinerary urns; but the Christian thought of death as sleep, brought with it into Christian speech the kindred thought of a chamber of rest, and embodied it in the word cemetery  (koimeterion) — the place to lie down to sleep.

The Christian's unique hope that  is not shared by non-believers is the Blessed Hope (see note Titus 2:13 cp 1Jn 3:2-3; see note 1Peter 1:13) of the return of Christ for His own just as He had promised (John 14:2-3). That will be the great resurrection day when living believers will be reunited with all their loved ones who have died. Believers then and now have this promise by the word of the Lord (see note 1 Thes 4:15) Himself Who declared to His disciples...

Let not your heart be troubled; believe in God, believe also in Me. In My Father's house are many dwelling places; if it were not so, I would have told you; for I go to prepare a place for you. And if I go and prepare a place for you, I will come again, and receive you to Myself; that where I am, there you may be also. And you know the way where I am going." (John 14:1-4)

THAT YOU MAY NOT GRIEVE AS THE REST WHO HAVE NO HOPE:  Hina me lupesthe (2PPPS) kathos kai oi loipoi oi me echontes (PAPMPN) elpida: (Genesis 37:35; Leviticus 19:28; Deuteronomy 14:1,2; 2 Samuel 12:19,20; 18:33; Job 1:21; Ezekiel 24:16-18; John 11:24; Acts 8:2) (1 Thes 4:17; Genesis 49:19; Zechariah 14:15; Matthew 24:31; 1 Corinthians 15:23; Philippians 3:20,21; 2 Thessalonians 2:1; Jude 1:14,15)

See related study on the Believer's Blessed Hope

So that (2443)  (hina) is a term of conclusion. Paul explains why he does not want them to be uninformed about the matter of a Christian who falls asleep.

You may not grieve - The negative particle (me) with the present tense indicates that the goal of the truth in this section is to stop the grieving of the readers. They are not to go on grieving as the rest. Paul's goal is to cure their grief by removing their ignorance.

Grieve (3076) (lupeo from lupe = sadness, sorrow, grief) means to feel pain, of body or mind and so to experience severe mental or emotional distress. It can also refer to physical pain which may be accompanied by sadness, sorrow or grief.

The present tense also speaks of the continual lot of those (the rest) who do not intimately know Christ as Lord and Savior (those with "no hope").

That you may not be continually sad, sorrowful, distressed. So this helps define those the rest = for one thing they have no hope. Whoa!

Apparently some of the saints in Thessalonica, despite having clearly been taught on some eschatological topics had ignorantly come to the conclusion that the saints who died would miss the Lord’s return and thus they were grieved over their absence at such a glorious event.

Vincent has some additional comments on the specific reason they might grieve about the believers who had died writing that..

Opinions differ as to the possible ground of this sorrow. According to some, the Thessalonians supposed that eternal life belonged only to such as should be found alive at the parousia, (coming of the Lord Jesus) and therefore that those already dead would not share the blessings of the Second Advent.

Others, assuming an interval between the Advent and the general resurrection, think that the Thessalonians were anxious lest their brethren who died before the Advent would be raised only at the general resurrection, and therefore would not share the blessings of communion with the Lord during the millennial reign.

It is impossible to decide the question from Paul's words, since he does not argue, but only consoles. The value of his consolation does not depend upon the answer to the question whether the departed saints shall first be raised up at the general resurrection, or at a previous resurrection of believers only. The Thessalonians were plainly distressed at the thought of separation from their departed brethren, and had partially lost sight of the elements of the Christian hope and reunion with them and fellowship with the Lord. These elements Paul emphasizes in his answer. The resurrection of Jesus involves the resurrection of believers. The living and the dead Christians shall alike be with the Lord. (Vincent, M. R. Word Studies in the New Testament. Volume 4:39)

We should not misunderstand what Paul is saying here about not grieving. He is not saying that believers are not to experience and express the normal sorrow that accompanies the death of a loved one which brings with it the pain of separation and loneliness. Even our Lord Jesus grieved over the death of His friend ("Jesus...was deeply moved in spirit and was troubled...Jesus wept" John 11:35). Although Jesus expressed sorrow, He did not despair over ever seeing His friend again. Normal human beings grieve over the physical death of their loved ones (see note Philippians 2:27). Paul is not saying Christians are to be dehumanized by removing grief from the realm of their experience. He goes on to qualify that the believer's grief is not as the rest, for the believer's goodbye is only temporary and our sure hope of reunion with our believing loved ones is forever!

As the rest - Paul draws a sharp distinction between Christians and all others, specifically all who are not believers in Christ. Earlier Paul had used a synonymous phrase outsiders (literally those without - see 1Thessalonians 4:12). One commentator has remarked on the difference between the terms outsiders versus the rest reasoning that the earlier expression outsiders implies exclusion, while the rest implies deprivation. In other words, non-believers are deprived of the hope and the associated comfort that believers possess when the truth regarding death is rightly understood.

Rest (3062)  (loipos = pertaining to the part of a whole which remains, the rest of the whole from leípo = to leave, lack) means the remaining, the remnant, the residue, the rest. Although loipos is an adverb, the NT uses it as a noun here and in other passages (Mt 22:6, Rev 11:13, 12:17, 19:21)

Have (2192)  (echo) means to hold on to. It means the rest (continually = present tense) have no hope to cling to.  Christians should not grieve over their dead loved ones like pagans do, as if they have no hope of ever seeing them again.  There is such a profound difference between a Christian funeral and a pagan funeral because believers possess this sure hope.

Hope (1680)  (elpis) (see also the Believer's Blessed Hope) is a desire of some good with expectation of obtaining it. Hope in Scripture is the absolute certainty of future good. In Hebrews 6:11 (note) hope is full assurance. In 1 Timothy 1:1 hope is not some abstract concept but is embodied in the Person and atoning world of Jesus Christ Jesus our Hope. 

Writing to the Philippians Paul confidently declares...

for to me, to live is Christ, and to die is gain (see note Philippians 1:21) (Comment: Paul is saying in essence that his  life found all its meaning in Christ and that even if he dies it is to his profit, because then there will be perfect union with Christ, without any of the limitations of this life, and the old flesh nature).

In marked contrast, in the face of death the pagan world stood in utter despair and abysmal hopelessness which "enshrouded" them as it rightly should. They vainly attempted to meet the certainty of death with grim resignation and bleak outlooks as stated by the pagan Aeschylus who wrote (incorrectly) that

Once a man dies there is no resurrection (Comment: Wrong! There is a resurrection for unbelievers but it is unto death, not life [see Order of Resurrection], see John 5:28-29 below)

Addressing the Athenians on Mars Hill Paul declared that...

having overlooked the times of ignorance, God is now declaring to men that all everywhere should repent, because He has fixed a day in which He will judge the world in righteousness through a Man Whom He has appointed, having furnished proof to all men by raising Him from the dead." Now when they heard of the resurrection of the dead, some began to sneer (this word stresses insulting another by contemptuous facial expression, phrasing, or tone of voice), but others said, "We shall hear you again concerning this." (Acts 17:30-32).

In John 5 Jesus declared...

Do not marvel at this; for an hour is coming, in which all (how many? all without qualification as to spiritually dead in Adam and sin or spiritually alive in Christ and salvation) who are in the tombs shall hear His voice, and shall come forth; those who did the good deeds (deeds don't save but they do indicate one is genuinely saved as James taught - James 2:14-26, see also notes on Romans 2:5-6)  to a resurrection of life (see notes on first resurrection in Revelation 20:5), those who committed the evil deeds to a resurrection of judgment (see notes on the second death - Revelation 20:11; 12;13; 14; 15). (John 5:28-29)

Paul writing the converted Gentiles in Ephesus exhorted them to...

remember that you were at that time separate from Christ, excluded from the commonwealth of Israel, and strangers to the covenants of promise, having (present tense = continually) no hope and without God in the world. (see note Ephesians 2:12)

Only believers have a sure hope (absolute certainty that God will do them good in the future) of life after death. The speculations of pagan philosophy do not amount to a hope but "I hope so". The "odds" are eternally against this type of hope, for the only sure, steadfast hope of eternal life with God is a hope that is built on nothing less than Jesus' blood and righteousness...

Christ Jesus our Hope (Literal rendering of 1 Timothy 1:1)

Milligan wrote that...

The general hopelessness of the pagan world in the presence of death is almost too well-known to require illustration (St. Paul's Epistles to the Thessalonians. 1908)

Theocritus rightly summarized the the hope of all outside Christ and still "in Adam" (and responsible to pay for the wages of sin which is death) wrote

There is hope for those who are alive, but those who have died are without hope.

Catullus echoes the tragic refrain...

When once our brief light sets, there is one perpetual night through which we must sleep. (Comment: Unfortunately, this is only partially correct, for in hell there is full consciousness not perpetual sleep, read Luke 16:19-32)

Lucretius wrote that...

No one awakes and arises who has once been overtaken by the chilling end of life

On pagan tombstones we read the hopeless carvings of their grim epitaphs

I was not
I became
I am not
I care not

An inscription has reportedly been found on a pagan tomb at Thessalonica which read...

After death there is no revival, after the grave no meeting of those who have loved each other on earth

As Paul so powerfully proclaimed in his last letter (just before he "fell asleep") God...

has saved us, and called us with a holy calling, not according to our works, but according to His own purpose and grace which was granted us in Christ Jesus from all eternity ("before the beginning of time" - NIV), but now has been revealed by the appearing of our Savior Christ Jesus, Who abolished death, and brought life and immortality to light through the gospel (See notes 2 Timothy 1:9; 1:10)

John MacArthur comments that...

Even though Paul’s ministry in Thessalonica was brief, it is clear the people had come to believe in and hope for the reality of their Savior’s return (cf. 1 Thessalonians 1:3, 1:9; 1:10; 2:19; 5:1; 5:2; 2Th 2:1,5). They were living in expectation of that coming, eagerly awaiting Christ. This verse (v13) (cf. 2Thes 2:1-3) indicates they were even agitated about some things that were happening to them that might affect their participation in it.

They knew Christ’s return was the climactic event in redemptive history and didn’t want to miss it. The major question they had was “What happens to the Christians who die before He comes? Do they miss His return?” Clearly, they had an imminent view of Christ’s return and Paul had left the impression it could happen in their lifetime. Their confusion came as they were being persecuted, an experience they thought they were to be delivered from by the Lord’s return (cf. 3:3,4). (MacArthur, John: 1 & 2 Thessalonians. Moody Press or Logos)

The Hope (Certainty) of Christ's Return at His Glorious Second Coming is a...

living hope (see note