Matthew 7:16

Yet He may seem here to have aimed under the title of false prophets, not so much at the heretic, as at those who, while their life is corrupt, yet wear an outward face of virtuousness; whence it is said, By their fruits ye shall know them. For among heretics it is possible many times to find a good life, but among those I have named never. And a hypocrite is easily discerned; for the way they are commanded to walk is a hard way, and the hypocrite is loth to toil. And that you may not say that you are unable to find out them that are such, He again enforces what He had said by example from men, saying, Do men gather grapes of thorns, or figs of thistles?

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 ye shall know them." For amongst heretics one may often find actual goodness, but amongst 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 therefor, when we see many such even now. Nay, for this too Christ foretold from the beginning. And see His gentleness: how He said not, "Punish them," but, "Be not hurt by them," "Do not fall amongst them unguarded." Then that thou mightest not say, "it is impossible to distinguish that sort of men," again He states an argument from a human example, thus saying, "Do men gather grapes of thorns, or figs of thistles? even so every good tree bringeth forth good fruit, but the corrupt tree bringeth forth evil fruit. A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit." Now what He saith is like this: they have nothing gentle nor sweet; it is the sheep only so far as the skin; wherefore also it is easy to discern them. And lest thou shouldest have any the least doubt, He compares it to certain natural necessities, in matters which admit of no result but one. In which sense Paul also said, "The carnal mind is death; for it is not subject to the law of God, neither indeed can be." And if He states the same thing twice, it is not tautology. But, lest any one should say, "Though the evil tree bear evil fruit, it bears also good, and makes the distinction difficult, the crop being twofold:" "This is not so," saith He, "for it bears evil fruit only, and never can bear good: as indeed in the contrary case also." "What then? Is there no such thing as a good man becoming wicked? And the contrary again takes place, and life abounds with many such examples." But Christ saith not this, that for the wicked there is no way to change, or that the good cannot fall away, but that so long as he is living in wickedness, he will not be able to bear good fruit. For he may indeed change to virtue, being evil; but while continuing in wickedness, he will not bear good fruit. What then? did not David, being good, bear evil fruit? Not continuing good, but being changed; since, undoubtedly, had he remained always what he was, he would not have brought forth such fruit. For not surely while abiding in the habit of virtue, did he commit what he committed. Now by these words He was also stopping the mouths of those who speak evil at random, and putting a bridle on the lips of all calumniators. I mean, whereas many suspect the good by reason of the bad, He by this saying hath deprived them of all excuse. "For thou canst not say, 'I am deceived and beguiled;' since I have given thee exactly this way of distinguishing them by their works, having added the injunction to go to their actions, and not to confound all at random."

(Serm. in Mont. ii. 24.) Wherefore it is justly asked, what fruits then He would have us look to? For many esteem among fruits some things which pertain to the sheep's clothing, and in this manner are deceived concerning wolves. For they practise fasting, almsgiving, or praying, which they display before men, seeking to please those to whom these things seem difficult. These then are not the fruits by which He teaches us to discern them. Those deeds which are done with good intention, are the proper fleece of the sheep itself, such as are done with bad intention, or in error, are nothing else than a clothing of wolves; but the sheep ought not to hate their own clothing because it is often used to hide wolves. What then are the fruits by which we may know an evil tree? The Apostle says, The works of the flesh are manifest, which are, fornication, uncleanness, &c. (Gal. 5:19.) And which are they by which we may know a good tree? The same Apostle teaches, saying, The fruits of the Spirit are love, joy, peace. (non occ.) But from their actions we may conjecture whether this their outward appearance is put on for display. For when by any temptations those things are withdrawn or denied them which they had either attained or sought to attain by this evil, then needs must that it appear whether they be the wolf in sheep's clothing, or the sheep in his own.

The grape has in it a mystery of Christ. As the bunch sustains many grapes held together by the woody stem, so likewise Christ holds many believers joined to Him by the wood of the Cross. The fig again is the Church which binds many faithful by a sweet embrace of charity, as the fig contains many seeds inclosed in one skin. The fig then has these significations, namely, love in its sweetness, unity in the close adhesion of its seeds. In the grape is shown patience, in that it is cast into the wine-press—joy, because wine maketh glad the heart of man—purity, because it is not mixed with water—and sweetness, in that it delighteth. The thorns and thistles are the heretics. And as a thorn or a thistle has sharp pricks on every part, so the Devil's servants, on whatsoever side you look at them, are full of wickedness. Thorns and thistles then of this sort cannot bear the fruits of the Church. And having instanced in particular trees, as the fig, the vine, the thorn, and the thistle, He proceeds to show that this is universally true, saying, Thus every good tree bringeth forth good fruit, but an evil tree bringeth forth evil fruit.

The fruits of a man are the confession of his faith and the works of his life; for he who utters according to God the words of humility and a true confession, is the sheep; but he who against the truth howls forth blasphemies against God, is the wolf.