10 I didn't mean that you should have nothing at all to do with outsiders of that sort. Or with crooks, whether blue- or white-collar. Or with spiritual phonies, for that matter. You'd have to leave the world entirely to do that! 11 But I am saying that you shouldn't act as if everything is just fine when one of your Christian companions is promiscuous or crooked, is flip with God or rude to friends, gets drunk or becomes greedy and predatory. You can't just go along with this, treating it as acceptable behavior. 12 I'm not responsible for what the outsiders do, but don't we have some responsibility for those within our community of believers?
Matthew Henry's Commentary on 1 Corinthians 5:10-12
Commentary on 1 Corinthians 5:9-13
(Read 1 Corinthians 5:9-13)
Christians are to avoid familiar converse with all who disgrace the Christian name. Such are only fit companions for their brethren in sin, and to such company they should be left, whenever it is possible to do so. Alas, that there are many called Christians, whose conversation is more dangerous than that of heathens!