Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 37

Chapter 37.—43.  Furthermore, according to our tenets, neither he of whom Petilianus said that he was cast forth by us for the sin of the men of Sodom, another being appointed in his place, and that afterwards he was actually restored to our college,—talking all the time without knowing what he was saying,—nor he whom he declares to have been penitent among you, in whatever degree their respective cases do or do not admit of any defense, can neither of them prejudice the Church, which is spread abroad throughout all nations, and increases in the world until the harvest.  For if they were really wicked members of it that you accuse, then they were already not in it, but among the chaff; but if they are good, while you defame their character with unrighteous accusations, they are themselves being tried like gold, while you burn after the similitude of chaff.  Yet the sins of other men do not defile the Church, which is spread abroad throughout the whole world, according to most faithful prophesies, waiting for the end of the world as for its shore, on which, when it is landed, it will be freed from the bad fish, in company with which the inconvenience of nature might be borne without sin within the same nets of the Lord, so long as it was not right to be impatiently separated from them.  Nor yet is the discipline of the Church on this account neglected by constant and diligent and prudent ministers of Christ, in whose province crimes are in such wise brought to light that they cannot be defended on any plea of probability.  Innumerable proofs of this may be found in those who have been bishops or clergy of the second degree of orders, and now, being degraded, have either gone abroad into other lands through shame, or have gone over to you yourselves or to other heresies, or are known in their own districts; of whom there is so great a multitude dispersed throughout the earth, that if Petilianus, bridling for a time his rashness in speaking, had taken them into consideration, he would never have fallen into so manifestly false and groundless a misconception, as to think that we ought to join in what he says:  None of you is free from guilt, where no one that is guilty is condemned.