They went out from us, but they did not belong to us. For if they had belonged to us, they would have remained with us. But their departure made it clear that none of them belonged to us.
19 They went out from us He anticipates another objection, that the Church seemed to have produced these pests, and to have cherished them for a time in its bosom. For certainly it serves more to disturb the weak, when any one among us, professing the true faith, falls away, than when a thousand aliens conspire against us.
Here is, I. A moral prognostication of the time; the end is coming: Little children, it is the last time, Jo1 2:18. Some may suppose that the apostle here addresses the first rank of Christians again; the juniors are most apt to be seduced, and therefore, "Little children, you that are young in religion, take heed to yourselves that you be not corrupted." But it...
Commenting on 1 John 2:18-19
They went out from us,.... Which intends not the persons that went down from Judea to Antioch, Act 15:1, who preached destructive doctrines to the Gentiles, which the apostles and the church of Judea disowned and censured; by which it appeared, that all the preachers of these doctrines were not of them, and of the same mind with them: for this sense makes these antichrists...