They went out from us, but they didn’t belong to us; for if they had belonged to us, they would have continued with us. But they left, that they might be revealed that none of them belong to us.
ExplanationCommentary
Verse 19. They were not of us, true and profitable members; though it can scarce be doubted but that some of them, at least for some time, truly believed: and by their going off, God was pleased to make it manifest that they were not of his faithful members. Such were Simon Magus, Cerinthus, Ebion, Nicolas of Antioch, and so forth Witham.—They, and so forth That is, they were not solid, steadfast, genuine Christians, otherwise they would have remained in the Church. Challoner.—The true note or mark of heresy, is the going out of or leaving the Catholic Church. God permitteth some to go out, that the true and tried faithful may be known.