You shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?
All Commentaries on Matthew 7:16 Go To Matthew 7
John Chrysostom
AD 407
And by the figure of false prophets, here, I think He shadows out not the heretics, but them that are of a corrupt life, yet wear a mask of virtue; whom the generality are wont to call by the name of impostors. Wherefore He also said further,
By their fruits you shall know them. Matthew 7:16
For among heretics one may often find actual goodness, but among those whom I was mentioning, by no means.
What then, it may be said, if in these things too they counterfeit? Nay, they will be easily detected; for such is the nature of this way, in which I commanded men to walk, painful and irksome; but the hypocrite would not choose to take pains, but to make a show only; wherefore also he is easily convicted. Thus, inasmuch as He had said, there be few that find it, He clears them out again from among those, who find it not, yet feign so to do, by commanding us not to look to them that wear the masks only, but to them who in reality pursue it.
But wherefore, one may say, did He not make them manifest, but set us on the search for them? That we might watch, and be ever prepared for conflict, guarding against our disguised as well as against our open enemies: which kind indeed Paul also was intimating, when he said, that by their good words they deceive the hearts of the simple. Let us not be troubled therefore, when we see many such even now. Nay, for this too Christ foretold from the beginning.