Church Fathers Commentary Matthew 7:15-20

"Beware of false prophets, who come to you in sheep`s clothing, but inwardly are ravening wolves. By their fruits ye shall know them. 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. Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. Therefore by their fruits ye shall know them." — Matthew 7:15-20 (ASV)

Pseudo-Chrysostom: The Lord had previously commanded His Apostles not to perform their alms, prayers, and fastings before men, like the hypocrites. So that they would know that all these things can be done in hypocrisy, He says, "Take heed of false prophets."

St. Augustine of Hippo: After the Lord said that there are few who find the strait gate and narrow way, He immediately added, "Take heed of false prophets," so that heretics, who often commend themselves for their small numbers, would not insert themselves into this teaching.¹

St. John Chrysostom: Having taught that the gate is strait, and because there are many who pervert the way that leads to it, He continues, "Take heed of false prophets." So that they might be more careful, He reminds them of what was done among their forefathers by calling these men "false prophets," for similar things happened even in that day.

Pseudo-Chrysostom: The statement, "the Law and the Prophets were until John" (Matthew 11:13), is made because there would be no more prophecy concerning Christ after He had come. Indeed, there have been and still are prophets, but they do not prophesy about Christ. Instead, they interpret the things prophesied about Christ by the ancients, that is, by the teachers of the Churches. For no one can unfold a prophetic meaning except by the Spirit of prophecy. The Lord, therefore, knowing that there would be false teachers, warns them of various heresies, saying, "Take heed of false prophets."

Because these false prophets would not be obvious unbelievers, but would lurk under the Christian name, He did not say "See," but "Take heed." A thing that is certain is simply seen or observed, but when it is uncertain, it must be watched or carefully considered. He says, "Take heed," because it is a sure precaution for safety to know the one you are to avoid. This warning does not imply that the Devil introduces heresies against God's will, but only by His permission. Because God does not want servants without trial, He allows them to be tempted; and because He does not want them to perish through ignorance, He warns them beforehand.

Furthermore, so that no heretical teacher could maintain that He was speaking here of Gentile and Jewish teachers and not of them, He adds, "who come to you in sheep's clothing." Christians are called sheep, and the sheep's clothing is a form of Christianity and of false religion. Nothing drives out all good like hypocrisy, for evil that puts on the appearance of good cannot be guarded against, because it is not recognized. Again, so that the heretic could not claim He is speaking of true teachers who are nevertheless sinners, He adds, "But inwardly they are ravening wolves." Catholic teachers, even if they are sinners, are spoken of as servants of the flesh, yet not as ravening wolves, because it is not their purpose to destroy Christians.

Clearly, then, He is speaking of heretical teachers, for they put on the guise of Christians so that they may tear the Christian to pieces with the wicked fangs of seduction. The Apostle speaks about such people, saying, "I know that after my departure fierce wolves will come in among you, not sparing the flock" (Acts 20:29).

St. John Chrysostom: Yet with the title of "false prophets," He may seem here to have been targeting not so much heretics as those who, while their life is corrupt, still wear an outward appearance of virtue. This is why it is said, "By their fruits you shall know them." For among heretics it is often possible to find a good life, but never among those I have just described.

St. Augustine of Hippo: Therefore, it is rightly asked what fruits He wants us to look for. For many consider certain things to be fruits that actually belong to the sheep's clothing, and in this way they are deceived about the wolves. For instance, they practice fasting, almsgiving, or praying, which they display before men, seeking to please those to whom these things seem difficult.²

These, then, are not the fruits by which He teaches us to recognize them. Deeds done with a good intention are the true fleece of the sheep itself, while those done with a bad intention, or in error, are nothing more than a wolf's clothing. But the sheep should not hate their own clothing just because it is often used to hide wolves.

What then are the fruits by which we can know an evil tree? The Apostle says, "The works of the flesh are manifest, which are, fornication, uncleanness, etc." (Galatians 5:19). And what are the fruits by which we can know a good tree? The same Apostle teaches, saying, "The fruits of the Spirit are love, joy, peace."

Pseudo-Chrysostom: A person's fruits are the confession of their faith and the works of their life. For whoever, in accordance with God, utters words of humility and a true confession is the sheep; but whoever, against the truth, howls blasphemies against God is the wolf.

St. Jerome: What is said here about false prophets can be applied to all whose dress and speech promise one thing, while their actions exhibit another. But it is especially to be understood of heretics who, by observing temperance, chastity, and fasting, surround themselves as it were with a garment of sanctity; but since their hearts are poisoned within, they deceive the souls of the simpler brethren.

St. Augustine of Hippo: But from their actions, we can discern whether their outward appearance is put on for show. For when, through any temptation, those things they had attained or sought to attain by this evil are withdrawn or denied to them, then it must become clear whether they are the wolf in sheep's clothing or the sheep in its own.³

St. Gregory the Great: The hypocrite is also restrained by the peaceful times of Holy Church and therefore appears clothed with godliness. But when any trial of faith follows, immediately the wolf, ravenous at heart, strips himself of his sheep's skin and shows by his persecution how great his rage is against the good.⁴

St. John Chrysostom: The hypocrite is easily recognized, for the way they are commanded to walk is a hard way, and the hypocrite is unwilling to labor. And so that you cannot say that you are unable to identify such people, He again reinforces what He said with a human example, saying, "Do men gather grapes of thorns, or figs of thistles?"

Pseudo-Chrysostom: The grape contained a mystery of Christ. As the bunch sustains many grapes held together by the woody stem, so also Christ holds many believers joined to Him by the wood of the Cross. The fig, in turn, is the Church, which binds many faithful in a sweet embrace of charity, just as a fig contains many seeds enclosed in one skin. The fig, then, signifies love in its sweetness and unity in the close adhesion of its seeds. The grape shows patience, because it is cast into the winepress; joy, because wine makes glad the heart of man; purity, because it is not mixed with water; and sweetness, because it delights.

The thorns and thistles are the heretics. Just as a thorn or a thistle has sharp pricks on every part, so the Devil's servants, from whatever side you look at them, are full of wickedness. Thorns and thistles of this kind, therefore, cannot bear the fruits of the Church. And having given examples of particular trees—like the fig, the vine, the thorn, and the thistle—He proceeds to show that this is universally true, saying, "Thus every good tree brings forth good fruit, but an evil tree brings forth evil fruit."

St. Augustine of Hippo: In this passage, we must guard against the error of thoseⁱ who imagine that the two trees refer to two different natures—one from God, and the other not. But we affirm that they can find no support for their view in these two trees, as will be evident to anyone who reads the context that He is speaking here of men.⁵

These men of whom we have spoken take offense at these two natures, not considering them according to their true usefulness. However, it is not by our advantage or disadvantage, but in and of itself, that nature gives glory to its Framer. All natures that exist, simply because they exist, have their own manner, their own appearance, and, as it were, their own harmony,ⁱ and are entirely good.⁶

St. John Chrysostom: But so that no one could say, "An evil tree indeed brings forth evil fruit, but it also brings forth good, and so it becomes hard to recognize, as it has two kinds of produce," for this reason He adds, "A good tree cannot bring forth evil fruit, neither can an evil tree bring forth good fruit."

St. Augustine of Hippo: From this saying, the Manichees suppose that neither can an evil soul possibly be changed for the better, nor a good soul for the worse. It is as if the verse had said, "A good tree cannot become bad, nor a bad tree become good," when in fact it says, "A good tree cannot bring forth evil fruit," nor the reverse. The tree is the soul—that is, the person themself—and the fruit is the person's works. An evil person therefore cannot do good works, nor a good person evil works. Therefore, if an evil person wants to do good things, they must first become good.

As long as a person continues to be evil, they cannot bring forth good fruits. Just as it is possible for what was once snow to cease to be snow, yet it is impossible for snow to be warm, so it is possible for one who has been evil to no longer be so. But it is impossible for an evil person to do good. For although they may sometimes be useful, it is not they who do it, but it comes from Divine Providence overseeing all things.⁷

Rabanus Maurus: A person is called a good tree or a bad tree according to their will, as it is good or bad. Their fruit is their works, which can be neither good when the will is evil, nor evil when it is good.

St. Augustine of Hippo: But while it is clear that all evil works proceed from an evil will, like fruit from an evil tree, from where will you say that this evil will itself has sprung? It can only be that the evil will of an angel sprang from an angel, and that of a man from a man. And what were these two before those evils arose in them? They were the good work of God, a good and praiseworthy nature.⁸

You see, then, that evil arises out of good, and there was nothing at all from which it could arise except what was good. I am speaking of the evil will itself, since there was no evil before it—no evil works, which could only come from an evil will as fruit from an evil tree. Nor can it be said that the will sprang out of good in the sense that it was made good by a good God, for it was made of nothing, and not of God.

St. Jerome: We would ask those heretics who affirm that there are two natures directly opposed to each other: if they admit that a good tree cannot bring forth evil fruit, how was it possible for Moses, a good tree, to sin as he did at the water of Meribah? Or for Peter to deny his Lord during the Passion, saying, "I do not know the man"? Or how, on the other hand, could Moses' father-in-law, an evil tree since he did not believe in the God of Israel, give good counsel?

St. John Chrysostom: He had not commanded them to punish the false prophets, and therefore He shows them the terrors of the punishment that comes from God, saying, "Every tree that does not bring forth good fruit is hewn down, and cast into the fire."

In these words, He also seems to be aiming at the Jews, and thus recalls the words of John the Baptist, who denounced punishment against them in the very same terms. For John had spoken to them in this way, warning them of the impending axe, the tree that would be cut down, and the fire that could not be extinguished.

But if one examines this somewhat closely, there are two punishments here: to be cut down and to be burned. Whoever is burned is also completely cut out of the kingdom, which is the harsher punishment. Many, indeed, fear nothing more than hell, but I say that the loss of that glory is a far more bitter punishment than the pains of hell itself. For what great or small evil would a father not undergo, so that he might see and enjoy his dearest son? Let us then think the same of that glory, for no son is so dear to his father as is the reward of the good: to depart and be with Christ. The pain of hell is indeed intolerable, yet ten thousand hells are nothing compared to falling from that blessed glory and being hated by Christ.

Glossa Ordinaria: From the preceding analogy, He draws the conclusion to what He had said before, which is now clear, saying, "Therefore by their fruits you will know them."⁹

1. Serm. in Mont., ii, 23
2. Serm. in Mont., ii, 24
3. non occ.
4. Mor., xxxi, 14
5. Serm. in Mont., ii, 25
6. City of God, book 12, ch. 4
7. Serm. in Mont., ii, 25
8. see Op. Imp. in Jul. v. 40
9. non occ.