Augustine of Hippo

But whether he or some partners of his error are with you—for they are too numerous to make it possible for us to hope they are not, and when they are not refuted they mislead others into their sect and increase so much that I do not know where they will break out next—we would rather see them cured in the body of the church than cut off from the body as rotten members, if necessity allows even that. We have to fear that others will be infected, if we spare their infection. But the mercy of our Lord is able rather to free them from disease, and no doubt he will do it if they note and hold faithfully to what is written: "Whoever shall call upon the name of the Lord shall be saved."