To Remain Sexually Pure
I Thessalonians 4:6:
Though some commentators have concluded that Paul shifts subjects from sexual to business ethics or general behavior in this verse, there is little to indicate such a shift. The NIV’s translation, which indicates a continuation of the previous discussion, is almost certainly correct; τῴ πράγματι (tō pragmati) most naturally signifies the “matter” under discussion, not “business” or “any matter” (AV). As the previous verse views the basis for Christian sexual ethics from a vertical perspective, so here Paul addresses the horizontal aspect. Sexual immorality not only violates the Christian’s bond with the Lord but also with fellow believers.
Paul uses two verbs with similar meanings to emphasize this point. “Wrong” translates ὑπερβαίνω (hyperbainō), which specifically indicates going beyond the prescribed boundaries and, as used here, causing injury to another. “Take advantage” represents πλεονεκτέω (pleonekteō), suggesting the attempt to gain something for oneself at the expense of another, “to cheat,” in other words. Both verbs are in the Greek present tense, indicating continuing action; they therefore point to a continual doing of harm through sexual immorality.
“Brother” here almost certainly points to other Christians, reflecting Paul’s particular concern for the effect of immorality on the unity and integrity of the church. But it is probably used generically to refer to either men or women (hence the NRSV’s “brother or sister”). In light of the statement of v. 5, Paul’s point probably includes the idea that by engaging in sexual immorality, motivated by the self-centered desire for gratification, one violates the sacred boundaries of the partner’s integrity and wrongfully takes from the partner something for selfish gain. Also cheated are the present or future spouses of both persons engaged in immorality because by the immoral act the exclusive bond of marriage is violated.
The Lord will punish men for all such sins, as we have already told you and warned you.
If immorality indeed involves the offenses noted in vv. 5–6a, then its wrong must be declared in divine judgment. To that subject Paul now turns. Literally he writes here, “because God is the one who brings justice concerning all these things.” Though immorality committed in secret may escape the notice of all but its participants, God brings to light that which is secret (Eph 5:8–14) in a judgment that is sure and final. The idea that sexual behavior is entirely a private matter, that it can be treated casually or that immorality has no victims or consequences is entirely incompatible with the existence of a just and almighty God who both establishes the standards of morality and brings retribution when the standards are disobeyed.
Again Paul draws attention to the fact that the Thessalonians had already received this moral teaching as a part of their initial instruction as Christian converts. Two verbs are used together to emphasize this point: προεῖπον (proeipon), meaning simply “to say beforehand,” and διαμαρτύρομαι (diamartyromai), emphasizing a solemn, serious warning. The fact that Paul has repeated this already-received injunction at the length and with the firm rhetoric found here is indicative of the seriousness of the issue.
Weatherly, J. A. (1996). 1 & 2 Thessalonians (1 Th 4:6). Joplin, MO: College Press Pub. Co.