Calvin's Commentaries, Vol. 31: Matthew, Mark and Luke, Part I, tr. by John King, [1847-50], at sacred-texts.com
15. But beware of false prophets, who come to you in sheep's clothing, but inwardly are ravening wolves. 16. From their fruits you shall know them. Do men gather grapes from thorns, or figs from thistles? 17. So every good tree yields good fruits, and a rotten tree yields bad fruits. 18. A good tree cannot yield evil fruits, nor can a rotten tree yield good fruits. 19. Every tree, which does not yield good fruit, is cut down, and is thrown into the fire. 20. Therefore from their fruits you shall know them.
43. For the tree is not good which yields rotten fruit; and the tree is not rotten which yields good fruit. 44. For every tree is known from its fruit: for men do not gather figs from thorns, nor from thorns do they gather grapes. 45. A good man, out of the good treasure of his heart, bringeth forth what is good, and a bad man, out of the bad treasure of his heart, bringeth forth what is bad. For out of the abundance of the heart his mouth speaketh.
Matthew 7:15. But beware of false prophets These words were intended to teach, that the Church would be exposed to various impositions, and that consequently many would be in danger of falling from the faith, if they were not carefully on their guard. We know what a strong propensity men have to falsehood, so that they not only have a natural desire to be deceived, but each individual appears to be ingenious in deceiving himself. Satan, who is a wonderful contriver of delusions, is constantly laying snares to entrap ignorant and heedless persons. It was a general expectation among the Jews that, under the reign of Christ, their condition would be delightful, and free from all contest or uneasiness. He therefore warns his disciples that, if they desire to persevere, they must prepare themselves to avoid the snares of Satan. It is the will of the Lord, (as has been already said,) that his Church shall be engaged in uninterrupted war in this world. That we may continue to be his disciples to the end, it is not enough that we are merely submissive, and allow ourselves to be governed by his Word. Our faith, which is constantly attacked by Satan, must be prepared to resist.
It is of the greatest consequence, undoubtedly, that we should suffer ourselves to be directed by good and faithful ministers of Christ: but as false teachers, on the other hand, make their appearance, if we do not carefully watch, and if we are not fortified by perseverance, we shall be easily carried off from the flock. To this purpose also is that saying of Christ:
“The sheep hear the voice of the shepherd; and a stranger
they do not follow, but flee from him,” (John 10:3, 5)
Hence too we infer, that there is no reason why believers should be discouraged or alarmed, when wolves creep into the fold of Christ, when false prophets endeavor to corrupt the purity of the faith by false doctrines. They ought rather to be aroused to keep watch: for it is not without reason that Christ enjoins them to be on their guard. Provided that we are not led astray through our own sluggishness, we shall be able to avoid every kind of snares; and, indeed, without this confidence, we would not have the courage necessary for being on our guard. Now that we know that the Lord will not fail to perform his promises, whatever may be the attacks of Satan, let us go boldly to the Lord, asking from him the Spirit of wisdom, by whose influences he not only seals on our hearts the belief of his truth, but exposes the tricks and impositions of Satan, that we may not be deceived by them. When Christ says, that they come to us in sheep’s clothing, but inwardly are ravening wolves, his meaning is, that they do not want a very plausible pretense, if prudence be not exercised in subjecting them to a thorough examination.
16. From their fruits you shall know them Had not this mark of distinction been added, we might have called in question the authority of all teachers without exception. If there is a mortal danger to be dreaded in teachers, and if we see no way of avoiding it, we shall be under the necessity of holding them all suspected: and there will be no better or shorter method than to keep our ears shut against them all. We see that ungodly men, to screen themselves when rejecting every kind of doctrine, hold out this danger, and that weak and ill-informed persons remain in a state of perplexity. That our reverence for the Gospel, and for its faithful ministers and teachers, may not be diminished, Christ enjoins us to form our opinion of the false prophets from their fruits It is with a very bad grace that the Papists, in order to excite hatred against us, quote directly this exhortation of Christ, Beware of false prophets, and by their clamors induce ignorant people to avoid us, without knowing why. But whoever desires to follow our Lord’s advice must judge wisely and with just discretion. For ourselves, we not only acknowledge freely that men ought to beware of false prophets, but we carefully and earnestly exhort simple people to beware of them. Only we warn them that, agreeably to the rule which Christ has laid down, they should first make a strict examination, that simple people may not reject the pure Word of God, and suffer the punishment of their own rashness. There is a wide difference between wise caution and perverse squeamishness. 476 It is a heinous wickedness in the Papists to repeal the command of Christ, by infusing into unhappy persons an unfounded dread, 477 which deters them from making inquiry. Let this be regarded by us as a first principl that those who tremblingly reject or avoid a doctrine unknown to them, act improperly, and are very far from obeying the command of Christ.
It now remains to be seen, what are the fruits which Christ points out. Those who confine them to the life are, in my opinion, mistaken. As pretended sanctity, and I know not what masks belonging to greater austerity of life, are frequently held out by some of the worst impostors, this would be a very uncertain test. Their hypocrisy, I do own, is at length discovered; for nothing is more difficult than to counterfeit virtue. But Christ did not intend to submit his doctrine to a decision so unjust in itself, and so liable to be misunderstood, as to have it estimated by the life of men. Under the fruits the manner of teaching is itself included, and indeed holds the chief place: for Christ proves that he was sent by God from this consideration, that
“he seeketh not his own glory,
but the glory of the Father who sent him,” (Joh 7:18.)
Is it objected, that few persons are endued with such acuteness, as to distinguish good fruits from bad? I answer, as I have already said: Believers are never deprived of the Spirit of wisdom, where his assistance is needful, provided they distrust themselves, renounce their own judgment, and give themselves up wholly to his direction. Let us remember, however, that all doctrines must be brought to the Word of God as the standard, and that, in judging of false prophets, the rule of faith holds the chief place. We must also consider what God enjoins on his prophets and the ministers of his word: for in this way their faithfulness may be easily ascertained. If, for example, we place before our minds what Paul requires in bishops, (1Ti 3:1-7; Titus 1:6-9,) that description will be sufficient of itself to condemn the whole mass of Popery: for the Popish priests seem as if they purposely intended to present an opposite picture. There is no reason to wonder, therefore, if they forbid men to form a judgment of false prophets. But this passage clearly shows, that their titles ought to go for nothing, and that not much regard ought to be had even to their calling, if those who receive the name of pastors, and are called to the office of teachers, do not faithfully answer to their charge.
Do men gather grapes from thorns, or figs from thistles? By these proverbs, which were then in common use and universally received, Christ confirms his statement, that no man can be deceived by false prophets, unless he is wilfully blind: for the fruits as plainly discover upright servants of God, and unfaithful workmen, as the fruits point out the nature of the tree.
Luke 6:43. For the tree is not good This statement, as related by Luke, appears to be a general instruction given by Christ, that by the fruits our opinion of every man ought to be formed, in the same manner as a tree is known by its fruit After having inserted the reproof to hypocrites, who “perceive a straw in the eye of another, but do not see a beam in their own,” (verses 41,42,) he immediately adds, For the tree is not good which beareth rotten fruit, nor is the tree rotten which beareth good fruit The illative particle γὰρ, for, appears to connect these two sentences. But as it is certain that Luke, in that sixth chapter, records various discourses of Christ, it is also possible that he may have briefly glanced at what is more fully explained by Matthew. I attach no great importance to the word for, which in other passages is often superfiuous, and appears obviously to be so from the concluding statement.
Luke 6:45. A good man, out of the good treasure of his heart, bringeth forth good Such is the statement with which Luke concludes the discourse; and I have no doubt that he intended to describe, without a figure, the kind of judgment which Christ orders us to make from the fruits Believers ought to examine carefully what kind of doctrine is taught by those who profess to be the servants of God. “Titles (he says) are of little value, till the speaker give actual evidence that he is sent by God.” Yet I am far from saying, that this passage may not be applied to a general doctrine, And certainly the last clause, out of the abundance of the heart his mouth speaketh, has a more extensive reference than to false prophets: for it is a common proverb. Is it objected, that the tongues of men lie, and that men of the worst hearts are often the best speakers? I reply: Christ merely points out here what is a very ordinary occurrence. For, though hypocrites express in words what is different from the feelings of their hearts, that is no reason why we may not justly and appropriately call the tongue the portrait of the mind.
“Il y a grande difference entre une bonne facon de se donner garde d'estre trompe, et un deboutement temeraire sans savoir pourquoy.” — “There is a great difference between a proper method of guarding against being deceived, and a hasty rejection without knowing, why.”
“Par une vaine crainte, qu'ils leur proposent;” — “by a vain dread which they hold out to them.”