1 Thessalonians 4

1 Paul transitions into the instructional part of this letter. He indicates that the instructions which follow are given in the authority of Christ and should be taken seriously.

It appears that Timothy, along with his good report, also brought questions about Christian conduct. Christians are to live in such a manner that we please God, not ourselves. Paul assures the Thessalonians that they are doing well, but that they could be doing better.

2 Paul had apparently discussed at least some of these instructional items while he was in Thessalonica, but he probably was not there long enough to develop some of them fully.
3 Christians are to undergo the process of sanctification. This is a life-long effort to be set apart for God's special use. This involves changes in our attitude and lifestyle as we align our words and actions with our faith. A Changed life is the Christian's own personal testimony to the world that God changes people for the better when they believe in Him.

Sanctification here does not refer to one's salvation. A Christian is holy before God because of his relationship with Christ, not because of his actions. However, the Christian will desire to live as God wants him to, and Paul lists several distinct behaviors as examples here.

Sexual immorality can be defined as any sexual activity outside the confines of a husband and wife marriage relationship. Jesus made it clear that this includes the thought life, not just the physical act (Mat 5:27-28). Most of the places where Paul started church had pagan cultures that emphasized sex - often promoted as religious rites. Paul had to emphasize several times that God is pleased with monogamous, committed relationships between a man and woman, and that other sexual scenarios were unacceptable in the Christian life.

4 "Vessel" here most likely refers to one's own body. Christians, with the assistance of the Holy Spirit, are to demonstrate self-control over their sexual desires. The Christian is to be sanctified both for God and for his or her spouse. In so doing, both God and the spouse are honored.
5 Those who do not know God vent their lust in all kinds of ways. Christians are to confine sexual interactions to their relationship with their spouse, and even then it is to be couched in love and respect.
6 While some translations render the phrase "any matter" in this first clause, apparently, the more accurate way would be "the matter" referring to the content of the previous verses. It is likely that Paul is specifically addressing adultery, where one man would "defraud" another by taking his wife. Paul reminds them of the strict warning he had given them about this in person. God does not view sexual immorality lightly. While the Christian is still saved, he can expect some kind of punishment for immoral behavior.
7 Three reasons are given for God's punishment of sin in the Christian's life. First, personal sin violates the calling, which God has given us. Christians call Him King and Lord, recognizing His authority in our lives. Thus, we give Him the right to determine how we should behave. We are to live for Him, not for ourselves. In practice, God's commands have both spiritual and practical value. The spiritual value of obedience is that we please God. In practical terms, sexually pure people under normal circumstances will not need to worry about venereal disease, divorce, etc. The world also tends to hold moral people with esteem, even if they do not agree with the Christian faith.
8 There were, and still are, those who discount the importance of sexual purity in a Christian's life. Paul tells them plainly that this is not merely a matter of rejecting a suggestion from a fellow human being. God commands purity. If a true Christian rejects God's word, he can expect spiritual difficulties since he is fighting against the Holy Spirit. As stated before, he might expect some other kind of punishment as well. Another problem in the early and modern church is with those who claim to be Christians, but are not. They make a mockery of God when they declare His lordship, but continue to practice their sinful behaviors. Such people generally "fake" Christianity for social or cultural reasons, but they do not understand that they do themselves more harm than good while offending God and marring the reputation of His people.
9 Paul now speaks on how Christians are to treat each other. He uses the Greek word philadelphias, "brotherly love", which was normally used to describe the love that existed within families. In many passages of Scripture, Christians are encouraged to see each other as brothers and sisters in Christ with God as our common Father. The Thessalonians were apparently doing an excellent job of loving one another in an appropriate way as the Holy Spirit was teaching them.

The church family can be especially important in mobile and individualistic societies where family support systems may be unavailable on a daily basis. Whether we are young or old, we all need to know we are loved and cared about. The church should provide for these needs in fellow believers whether they have close contact with their "natural" families or not.

10 The Thessalonians did not confine their love to their own church body. They understood that God's love extended to other churches as well. They had apparently done some tangible actions that demonstrated that they loved people in other churches.

Yet, Paul does not want them to be complacent. They are to continue to grow in their love for one another. Love takes continual effort. It needs to be demonstrated frequently. In many modern churches in the United States, people are still very individualistic. We often seem reluctant to get to know members of our congregations, help them when they need it, or ask others for help when we need it. In some churches, suspicion and fighting abound as a result. Clearly, there are some very good examples of churches practicing brotherly love, but in every case we are encouraged to love each other more. Christians are to be the living example of God's love in the world today. Worldly people mock broken churches, but will respect and perhaps be attracted to loving ones.

11 A Christian's ambition should not be to be the most prominent, recognized, or famous person in their community. Pride leads to these kinds of ambitions. We are encouraged to be more like servants: helping others, but doing so in a quiet way. If anything, we want to bring attention to God, not to ourselves.

Christians are not to be people who meddle in the affairs of others. This is not talking about things like accountability or church discipline. It does include things like gossip and trying to control or direct other people's lives for them. We can explain options and teach people how to weigh them, but we cannot make choices for them. This almost always causes resentment on the part of the recipient.

One of the problems that came up in the early church was people not working for a living. The teachings about the Resurrection are almost always portrayed as urgent and imminent. Some people concluded that if the end of the world was coming soon, they had no need to continue working. The generosity of the saints undoubtedly fostered this. Those who had food and money were contributing to the common fund, which anyone could draw from as they had need. Those who quit their jobs simply lived off other people's labor. God created us to work, not be lazy. Since we do not know when the Last Day will be, it is important that we live as best we can, which includes having an occupation that will support ourselves and our immediate family. If someone has been blessed with a career that exceeds his own needs, he is to generously share with others who do have needs.

12 A Christian's behavior is supposed to be exemplary, whether in the Church or the community. If anything, we are to contribute in a positive manner, not take advantage of it. A Christian is not supposed to do things like live off of welfare, for instance, if he can work and jobs are available. Society tends to look down on freeloaders, and Christians are not to be counted among them.
13 There was apparently a question about what happened with Christians who had died. The doctrine of the resurrection may have been one that Paul had not had time to fully explain to the believers in Thessalonica. It appears they did not understand that the Resurrection meant that those who had died would rise again.

Paul is not telling us it is wrong to mourn. When someone dies, we can expect sadness because of the separation, especially if we were emotionally close to the person. However, Christians know that death is not a permanent condition. Thus our mourning should be tempered with hope. Jesus Himself gives an example in John 11. His friend Lazarus had died, and Jesus mourned even though He knew He was about to raise Lazarus from the dead in just a matter of minutes.

14 Paul assures them that those who had died would come back to life again at the Resurrection. The evidence for this hope was in the resurrection of Jesus.
15 Paul told the Thessalonians that the teaching he gave was directly from Jesus. He assured them that the dead would not be left behind in the Rapture. He also asserted that there is no disadvantage in having died before that Day.
16 In fact, the Resurrection will precede the Rapture. The Resurrection is when the dead will be brought back to life, and the Rapture is when all of God's people will be caught up to Him in the air.

The Second Coming of Christ will precede the Resurrection. This will be an unmistakable event that the whole world will witness (Luke 17:23-24). Similar to how kings of the earth are honored with shouts and trumpet fanfares, so will Christ, except that His announcement will come from heaven.

17 After the Rapture, we will be with God forever. The Body of Christ (i.e., the Church) will be joined with the Head (i.e., Christ). The reunion occurs in the air, perhaps to demonstrate Christ's authority everywhere - be it earth, air, or heaven. The Bible teaches that at some point after this, Christ will establish His kingdom on earth, but the timing and other details are not made clear in the Scriptures.
18 This teaching should be sufficient to keep Christians from feelings of hopelessness when they mourn for a fellow believer who dies. They will see them again one day, and after that no one will fear death again.