What does 2 Thessalonians 3:15 mean?

In the prior verse, Paul commanded that those who claim to be Christians but exhibit laziness are to be put to shame and avoided by other believers. The intent there, as in all such instructions in the New Testament, is to encourage the offender to repent and be restored (Galatians 6:1).

Here, Paul interjects a note of compassion into the concept of withdrawing social contact from an unrepentant offender. He exhorts his readers to avoid considering the offender an enemy. Instead, they should consider him a brother, and treat these actions as a loving means of correction. Breaking off social contact with him was going far enough. There was no need to treat him as an outcast by breaking off all contact with him.

We should also note that this passage, combined with 1 Corinthians 5 and Matthew 18:15–20, presents a spectrum of responses to sin within a congregation. The more serious the sin, it seems, the more overtly the church ought to insist on separation until the offender repents. All of this, however, is meant to be done with a loving goal in mind: the restoration of the one who is sinning!

When a Christian deserves church discipline, a church can do wrong in two ways. It can overlook the wrong and take no action. Or it can go too far in regards to the offender by treating him like an enemy, speaking harshly about him, and cutting him off from all contact with the church. Because believers are brothers in the same family, we should treat an offending brother with compassion. We must lovingly confront his wrongdoing, but graciously help him repent and be restored to fellowship with God and his fellow believers. While it's crucial that churches exhibit holiness as part of our witness to the world (1 Peter 2:12), shooting our wounded is never a good option.