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.
that they might be made manifest that they were not all of us; the word "all" is left out in the Syriac version. The defection and apostasy of these persons were permitted by God, that it might appear they had never received the grace of God in truth; and their going out was in such a manner, that it was a certain argument that they were not of the elect; since they became antichrists, denied the deity or sonship of Christ, or that he was come in the flesh, or that he was the Christ, and therefore are said to be of the world, and not of God, 1 John 2:22, so that this passage furnishes out no argument against the saints' perseverance, which is confirmed in 1 John 2:20.