At the end of chapter 3, Paul tells us readers something that many of us probably don’t want to hear and will try our best to reject out of hand: How our choice to remain faithful or to be unfaithful affects others is our responsibility not theirs; the onus is on watched and not the watcher.

Finally then, brothers and sisters, we request and urge you in the Lord Jesus, that as you received instruction from us as to how you ought to walk and please God (just as you actually do walk), that you excel even more. 2 For you know what instructions we gave you by the authority of the Lord Jesus.
Paul encourages the church to keep being faithful and to keep striving for righteousness; he reminds them here that they already know what to do and how to live.

“3 For this is the will of God, your sanctification; that is, that you abstain from sexual immorality; 4 that each of you know how to possess his own vessel in sanctification and honor, 5 not in lustful passion, like the Gentiles who do not know God; 6 and that no one violate the rights and take advantage of his brother or sister in the matter, because the Lord is the avenger in all these things, just as we also told you previously and solemnly warned you. 7 For God has not called us for impurity, but in sanctification. 8 Therefore, the one who rejects this is not rejecting man, but the God who gives His Holy Spirit to you.”

Finally, after three chapters, we perhaps catch a glimpse as to why Paul has written to the Thessalonians. The Greek word porneia—translated here in verse three as “sexual immorality”—although it can mean from prostitution to incest to sexual immorality to unchastity or even to idolatry—tells us at least one of the church’s temptations.

Paul states that holiness is the will of God. This is the first time in his writings that the apostle declares something to be God’s will. First and foremost, it is God’s will that believers live in a way that is pure, good, and unlike how the world would have you live. In this case, the Thessalonians first sign of holiness—of specifically sanctification—is to “abstain from sexual immorality”, porneia; human behavior and God’s will are hereby linked. Later on scripture, remember what Jesus says to Peter: “If you love me, you will feed my sheep and care for my lambs.”

To be sanctified—to be holy—is to set aside and dedicated to God’s purposes. Put another way, it is to put God’s needs first. Also important here is the fact that we do not become holy by abstaining from porneia. But we abstain from porneia BECAUSE we have been made holy. Remember Galatians: Christ is first. So Paul’s message in this passage can be summed up as: God has made you holy, so don’t do “x,y,z”.

In verse 4 Paul writes:
“4 that each of you know how to possess his own vessel in sanctification and honor, 5 not in lustful passion, like the Gentiles who do not know God…”

The holy—sanctified and set apart—person is not controlled by his or her sexual appetites. This is a matter of learning—"that each of you know how to”—and appears to be able to be in our wheelhouse. We can choose “to possess” our bodies and not be swept away in our base urges or “lustful passions”.

We learn at the end of verse 5 that this ability to control our urges derives from knowing God. Again, honorable and pure sexual behavior is preceded by God’s will for holiness. I say honorable and pure sexual behavior because Paul does not say here that the Thessalonians must be abstinent; only that they should not be sexually immoral and slaves to baser sexual desires.

What Paul means in verse 6 is something that folks just can’t quite agree upon. Some think that it is a continuation of Paul’s exhortation on sexual immorality and others think the apostle is speaking about another kind of impurity. Let me give you the options and you can be the judge. Let’s look.

“ 6 and that no one violate the rights and take advantage of his brother or sister in the matter, because the Lord is the avenger in all these things, just as we also told you previously and solemnly warned you.”

In the former position (that this verse is still about sex) the thinking is that Paul is warning the Thessalonians to not engage in illicit sex with one another. Perhaps 3-5 concern avoiding the attitudes and desires that lead to sexual immorality and that verse six is a specific warning about hubba-hubba-ing with fellow church members. Or maybe more specifically that no one use the special relationship that Christians within the church have with one another in order to gratify themselves.

For the latter position (that Paul is changing the subject from verses 3-5) some scholars argue that Paul is talking about the need to maintain honorable business practices in with fellow church members: “don’t violate the rights and take advantage of…” Here, sanctification involves avoiding sexual immorality and lust, controlling your bodily urges, AND dealing honestly with one another. This is not an unreasonable position, especially in light of what Paul writes in verses 10 and 11. Impure desires are not exclusively sexual in nature.

“7 For God has not called us for impurity, but in sanctification.”

Christians are called “in sanctification.” Again, this act of God comes first, and then we choose how to respond. All in all, this is a restatement of verse three. Paul REALLY wants to make this clear to the Thessalonians.

“ 8 Therefore, the one who rejects this is not rejecting man, but the God who gives His Holy Spirit to you.”
And since our transformation starts with Christ—see the last series on Galatians—we best pay attention to Paul’s instruction. Our practices must be in alignment with what God has done and is doing. If they are not, we are not rejecting a human being’s instruction but “the God who gives His Holy Spirit to you.”

By using this phrase, I think Paul is linking back to something that he teaches in Galatians: that the descendant of Abraham that will bless the world is only Jesus Christ, and He blesses us with the Holy Spirit. And it is only through the power of the Spirit that we can die to ourselves so that Christ may live in us. So, to put this into the context of what Paul has been saying in this section of 1 Thessalonians:
Our natural state is one of sexual immorality. It is one of lust. It is one where we are controlled by our urges. God sanctifies us with the Holy Spirit through Christ so that we might live through Him. Through the presence of that same Spirit, we come “to possess his own vessel in sanctification and honor”. But if we continue in sexual immorality, even though we don’t have to, since we have the Spirit, we are telling God that we want none of what He is offering.

“ 9 Now as to the love of the brothers and sisters, you have no need for anyone to write to you, for you yourselves are taught by God to love one another; 10 for indeed you practice it toward all the brothers and sisters who are in all Macedonia. But we urge you, brothers and sisters, to excel even more, 11 and to make it your ambition to lead a quiet life and attend to your own business and work with your hands, just as we instructed you, 12 so that you will behave properly toward outsiders and not be in any need.”

God has taught the Thessalonians to love each other, and they do! They philadelphia one another to be precise. They are a family, brothers and sisters, and they even include the Christians “in all Macedonia” in the family. But Paul thinks that they can do better, can “excel even more”. They can do better by extending that love for one another even to outsiders. “make it your ambition to lead a quiet life and attend to your own business and work with your hands…so that you will behave properly toward outsides and not be in any need.”

If the Christian has the right desire and focuses on his or her life, if believers live into God’s sanctification and strives for His will, they will have no need. There will be nothing missing from their lives. I think Paul implies here that this immorality and, perhaps, usury comes out of a sense of need. It makes life all about trying to fill the empty places in our hearts and lives. To put this another way, the less faithful we are to God, the more our lives will lack.