Augustine of Hippo, on 1Cor 11:19

“For there must be also heresies: that they also, who are approved, may be made manifest among you.”

“People become heretics, even though they would still have held wrong opinions if they had remained within the church. Now that they are outside, they do us more good, not by teaching the truth, for they do not know it, but by provoking carnal Christians to seek the truth and spiritual Christians to expound it. In the church there are innumerable people who are approved by God, but they do not become manifest among us as long as we are content with the darkness of our ignorance and prefer to sleep rather than to behold the light of truth.”

Imported from an open dataset — not yet checked against the printed edition.