Tertullian, on 1Cor 11:19

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

“The character of the times in which we live is such as to call forth from us even this admonition, that we ought not to be astonished at the heresies (which abound) neither ought their existence to surprise us, for it was foretold that they should come to pass; nor the fact that they subvert the faith of some, for their final cause is, by affording a trial to faith, to give it also the opportunity of being "approved." Groundless, therefore, and inconsiderate is the offence of the many who are scandalized by the very fact that heresies prevail to such a degree.”

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