A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.
All Commentaries on Matthew 7:18 Go To Matthew 7
John Chrysostom
AD 407
Jesus also said these things to shut the mouths of those who say nothing but slander and to reign in the lips of those who speak maliciously. For many are suspicious of good people because so many others are evil, but Jesus by this saying has deprived them of all excuse. For on this premise one would not even be able to say, “I am deceived and was misled.” For he has provided you a rule by which accurately to identify the frauds by their deeds. He has also commanded you to proceed on the basis of practices and not to mix up all cases at random. The Gospel of Matthew, Homily
