11 But now I have written to you, if any one called brother be fornicator, or avaricious, or idolater, or abusive, or a drunkard, or rapacious, not to mix with [him]; with such a one not even to eat. 12 For what have I [to do] with judging those outside also? ye, do not ye judge them that are within? 13 But those without God judges. Remove the wicked person from amongst yourselves.
Matthew Henry's Commentary on 1 Corinthians 5:11-13
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!