Passage
For this is the will of God, your sanctification: that you abstain from sexual immorality;
For this is the will of God, your sanctification: that you abstain from sexual immorality;
1 Thessalonians 4:1 Finally then, brothers, we ask and exhort you in the Lord Jesus, that as you received from us as to how you ought to walk and please God (just as you actually do walk), that you excel still more.
1 Thessalonians 4:2 For you know what commandments we gave you through the Lord Jesus.
1 Thessalonians 4:3 For this is the will of God, your sanctification: that you abstain from sexual immorality;
1 Thessalonians 4:4 that each of you know how to possess his own vessel in sanctification and honor,
1 Thessalonians 4:5 not in lustful passion, like the Gentiles who do not know God;
The verse centers on "will of God", "sanctification", "abstain", "sexual", and "immorality". It is saying that the verse draws attention to "will of God" and "sanctification", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 2's "For you know what commandments we gave..." into verse 4's "that each of you know how to...", so "will of God" and "sanctification" belong inside that flow. In 1 Thessalonians context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "will of God" and "sanctification" with trust shaped by these words, not by a vague optimism outside the passage.