1 Thess 4:1 – 12 begins Paul's discourse in addressing the Christian behavior that the Thessalonians should exhibit. Prior to this discourse, Paul establishes his apostleship, by expounding upon his missionary behavior in the previous chapter. He argues that his visit with his companions was not in vain. They proclaim and live the gospel, which indicates behavior worth imitating by the Thessalonians. In chapter 4; however, Paul provides specific instruction to the Thessalonians on how they should walk before God. This specific instruction transitions the letter from friendship to moral exhortation. The moral exhortation addresses information received from Timothy during his visit with the Thessalonians. Paul overarching goal is to encourage the Thessalonians' ethical progression as Christians.
Paul's "appeal to, urge, exhort, encourage" to Thessalonians includes abstaining from sexual immorality and excelling in possessing godly lives. Paul declares that the abstaining from sexual immorality is God's will and provides their "holiness, consecration, sanctification". The Greek lexicon denotes the term, ἁγιασμός to mean sanctification. However, the TDNT states that sanctifying best defines ἁγιασμός rather than sanctification. It contends that sanctification is accomplished through atonement. This process of atonement renders the person holy. In addition, ἁγιασμός represents the moral goal of purity that exists in physical life. Therefore, Paul reminds the Thessalonians God's commandments of being sanctified, which indicates the continual process of being rendered holy through the atoning sacrifice of Christ. The continual process occurs, when they abstain from sexual immorality. Paul also uses descriptive language to indicate the severity of sexual immorality. It not only renders them impure and fuels lustful passions, but it also reveals them "committing an offense" to God. Instead of rejecting God, Paul commands the Thessalonians to maintain a life and conduct that pleases God. This life is contrary to the idlers within the fellowship who were influenced by their belief that the second coming was near. The idlers reasoned that they did not have to work, but instead took advantage of the brotherly love. Paul, however, commands the Thessalonians to love others, lead a quiet life, attend to one's own affairs, and work with one's own hands. The outcome of such behavior renders respect to outsiders and ensures that no one has needs.