(1) Finally, then, brothers, we ask and urge you in the Lord Jesus, that as you received from us how you ought to walk and to please God, just as you are doing, that you do so more and more. (2) For you know what instructions we gave you through the Lord Jesus. (3) For this is the will of God, your sanctification: that you abstain from sexual immorality; (4) that each one of you know how to control his own body in holiness and honor, (5) not in the passion of lust like the Gentiles who do not know God; (6) that no one transgress and wrong his brother in this matter, because the Lord is an avenger in all these things, as we told you beforehand and solemnly warned you. (7) For God has not called us for impurity, but in holiness. (8) Therefore whoever disregards this, disregards not man but God, who gives his Holy Spirit to you.
Though the issue throughout Paul's passage, particularly vv. 3-5, is the condemnation of general sexual immorality, once he arrives at verse 6 the issue becomes adultery (4:6). Paul may have heard of a specific instances in this congregation, or he may still be concerned because of the known sexual looseness of pagans, reinforced during his stay in proverbially immoral Corinth. Unmarried Greek men (i.e., Greek men below the age of thirty) commonly indulged in intercourse with prostitutes, slaves and even other males. Greek religion and culture did not provide any disincentive for doing so.
In this passage, Paul begins with a reminder. He uses language that scholars call traditioning: passing on an earlier teacher’s words. Paul and his companions spent much of their time in Thessalonica teaching the new believers Jesus’ sayings, to some of which he plainly appeals in 1 Thessalonians 4:13–5:11.
He urges his listeners and readers to abstain from sexual immorality. Greek and Roman practice allowed for intercourse with prostitutes and slaves; premarital sex was prohibited for males under Roman law only if an aristocrat were doing it with an upper-class woman (this was called stuprum).
Judaism was much stricter, reserving sex for marriage (although evidence suggests some Jewish men did fall prey to premarital and extramarital temptations). What Paul does here is condemn all sexual immorality, although he moves to a specific example in 4:6. He shares the Old Testament view that premarital sex with someone other than one’s future spouse is adultery against one’s future spouse and thus as sinful as other adultery (Deut 22:13–29). (This statement does not imply that premarital sex with one’s future spouse was not prohibited in Judaism by the Old Testament view of marriage as covenant; it is only to affirm that premarital sex with anyone else was viewed as a capital offense against one’s future spouse.)
Paul uses the language in verse 4 of controlling one's “vessel” (KJV, NASB) or “body” (NIV, NRSV). In Greek and Diaspora Jewish literature; this phrase was occasionally applied to one’s wife (in some Jewish texts and, on one interpretation, in 1 Pet 3:7). It probably means “body” here, although the matter is not beyond dispute. Does this verse say that the Thessalonians should exercise control over their own bodies or that, in order to avoid sexual immorality, the single men should acquire wives? Or is this a teaching about how married men are to live with their wives in sanctification and honor?
Is it possible to find some other texts that might help illuminate or clarify the sense in the present verse? Some have observed that in 1 Corinthians 7:2 Paul presents what appears to be a teaching that is strikingly similar to 1 Thessalonians 4:3–4, “But since there is so much immorality (porneias, ‘sexual immorality’ as in 1 Thess. 4:3), each man should have his own (heautou, as in 1 Thess. 4:4) wife, and each woman her own husband” (cf. 1 Cor. 7:8–9).
Whatever the case, Paul makes it clear that it is the will of God that we be self-controlled. If "vessel" or "body" is indeed the wife, then Paul is saying that each man must learn to live with his own wife, and each woman must learn to live with her own husband, and fornication is to be shunned as contrary to God’s holy will. Instead of indulging in a life of sin and shame, we should behave ‘in a way that is holy and honorable’ in the sight of God. The pagan, from their ignorance of God, sink into ‘passionate lust’, a lifestyle that is utterly opposed to a saving knowledge of God. For a Christian to follow such shameful conduct is incomprehensible, for it is to exchange light for darkness, liberty for bondage, and life for death. It makes no sense for a Christian, who has crucified the flesh with its evil affections and lusts, to resurrect that flesh by gratifying its sinful cravings.
Paul elsewhere sees marriage as the only appropriate place to release passion (1 Cor 7:2–9), and of course it is likely that he opposes only adulterous passion (1 Thess 4:6), not sexual pleasure in marriage. Although many of Paul’s readers are ethnically Gentiles, he expects them to recognize that they are spiritually non-Gentiles by virtue of their conversion to the biblical faith (cf. Rom 2:29).
In verse 6, Paul tackles adultery. "Wife stealing” as it was often considered at the time, was punishable by banishment under Roman law; in some circumstances, a couple caught in the act could be killed on the spot. Adultery seems to have been common and usually unpunished, however; but a husband who learned that his wife was committing adultery was required by law to divorce her or himself be prosecuted on the charge of lenocinium—“pimping.” Palestinian Judaism could no longer execute the Old Testament death penalty for adultery, but Jewish people believed that what they could not execute, God would (especially on the day of judgment). Paul's point here is that in the matter of sexual immorality no one should violate his neighbor’s rights by committing adultery with his wife. To steal another man’s wife or daughter for sexual pleasure is to rob him of what rightfully belongs to him. Adultery is not only a sin against God, but a sin against a fellow human being.
In verse 7 Paul reminds that we are called to “sanctification” (NASB) or “holiness,” being “set apart” to God; Israel in the Old Testament was “set apart” and exhorted therefore to live as if they were set apart (to be holy as God was holy; e.g., Lev 20:24–26). All who refuse to tread the path of sanctification will be dealt with severely by the Lord Jesus on the Day of Judgement, if not before. The writer to the Hebrews says, ‘Marriage should be honored by all, and the marriage bed kept pure, for God will judge the adulterer and all the sexually immoral’ (Heb. 13:4).
In our sex-mad society of the twenty-first century, where morals are frowned upon and immorality is common place, the Christian must stand strong and with his life and acknowledge that he has been called out of impurity to ‘live a holy life’. It is inconceivable that a holy God should call us to any kind of uncleanness; instead, his commands are unambiguous: ‘As obedient children, do not conform to the evil desires you had when you lived in ignorance. But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy” ’ (1 Peter 1:14–16). Holiness should be the element in which a Christian daily moves.
A Christian who shows contempt for God’s law is showing contempt for God himself, who gives us his Holy Spirit. The special characteristic of the Holy Spirit, who lives in every believer, is holiness. Therefore, to live in an unholy manner while receiving the gift of the Holy Spirit is both insulting and grievous to God. To walk in such a way is to move him to withdraw from us.
Every Christian should be filled with the Holy Spirit, who arms us against immorality and helps us to put to death the acts of the sinful nature. ‘For if you live according to the sinful nature, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live’ (Rom. 8:13).