Augustine of Hippo

It is true that some take the phrase “from your midst” to mean that each one is to expel the wickedness out of oneself in order to be good. But, no matter how it is interpreted, whether that the wicked in the church are checked by the severity of excommunication or whether each one by self-blame and self-discipline drives wickedness out of himself, there can be no misunderstanding of the teaching of the apostle in the passage of Scripture just quoted: we are to refrain from association with brothers who are accused of any of the vices mentioned above, that is, with those who are notoriously scandalous. With what intention and with what charity this merciful severity is to be administered is evidenced not only by his statement, “that his spirit may be saved in the day of our Lord Jesus Christ,” but appears elsewhere even more clearly where he says, “if anyone does not obey our word by this letter, note that man and do not associate with him, that he may be put to shame. Yet do not regard him as an enemy, but admonish him as a brother.”