10 yet not at all meaning with the sexual sinners of this world, or with the covetous and extortioners, or with idolaters; for then you would have to leave the world. 11 But as it is, I wrote to you not to associate with anyone who is called a brother who is a sexual sinner, or covetous, or an idolater, or a slanderer, or a drunkard, or an extortioner. Don’t even eat with such a person. 12 For what have I to do with also judging those who are outside? Don’t you judge those who are within?
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!