Commentary - Matthew 7:15-20

Bird's-eye view

In this famous and critically important passage, the Lord Jesus transitions from the broad way and the narrow way to the subject of discerning who is actually on which path. Having just warned about the gate that leads to destruction, He now warns about the guides who lead people through it. The central issue here is the detection of false prophets. Jesus provides His disciples with a necessary, rugged, and agricultural test: you will know them by their fruits. This is not a call for suspicious, nit-picking criticism, but rather for sober-minded, agricultural realism. A tree is what it produces. A teacher is what he is. The passage is a profound warning against being deceived by mere appearances, by the soft wool of sheep's clothing that can conceal a ravenous wolf. It establishes an unbreakable link between a person's core identity (the tree) and their life's output (the fruit), culminating in a stark warning of fiery judgment for all that is fruitless and false.

This is practical divinity at its finest. The church is a flock, and shepherds must be vigilant against wolves. Jesus arms the ordinary believer with the tools for this vigilance. The test is not academic credentials, oratorical skill, or personal charisma. The test is fruit. This principle is foundational for church discipline, for choosing elders, and for the personal task of discernment that every Christian must engage in. The stakes are as high as they can be, because bad trees are not just unproductive; they are destined for the fire.

Outline

Context In Matthew

This passage comes near the end of the Sermon on the Mount, which is the foundational ethical and doctrinal manifesto of the Kingdom of God. Jesus has laid out the character of the kingdom citizen (the Beatitudes), the relationship of the kingdom to the law of Moses (fulfillment, not abolition), and the practices of kingdom righteousness (in contrast to the hypocrisy of the Pharisees). He has just presented the choice between the two ways, the broad and the narrow (Matt 7:13-14). The warning against false prophets is the logical next step. If there is a narrow way that leads to life, it is certain that there will be false guides who try to lead people down the broad way, all the while promising them that it is the way of life. This section, along with the subsequent warnings about false professions of faith (Matt 7:21-23) and the parable of the two builders (Matt 7:24-27), forms the concluding application of the entire sermon. It is a call to discernment, to genuine faith, and to obedient living as the only solid foundation.

Key Issues

The Orchard of God

The controlling metaphor here is agricultural, and we must think like farmers to understand it. A farmer does not get angry at a thistle for not producing figs. He simply recognizes it for what it is and acts accordingly. He knows that the nature of the plant determines the nature of its fruit. This is a fixed law of the created order, and Jesus applies it directly to the spiritual realm. What a person is on the inside, in their heart, will inevitably, necessarily, and publicly manifest itself in their life.

This cuts right through all our modern therapeutic nonsense and our gnostic tendencies to separate the "real me" on the inside from the things I actually do and say. Jesus will have none of it. The fruit doesn't just give a clue about the tree; it reveals the tree. This is why the apostle James can say that faith without works is dead. A faith that produces no fruit is not a sick tree; it is a dead tree, a bad tree. The works, the fruit, are the animating principle of the faith. As James says, the body without the spirit is dead, and so faith without works is dead also. The fruit is the life of the tree made visible. To claim to be a good tree while producing bad fruit is not just a contradiction; it is an impossibility in the world God has made.

Verse by Verse Commentary

15 “Beware of the false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves.

The command is direct: Beware. This is a call to be on guard, to be vigilant. The danger is not from overt, snarling enemies who announce their intentions. The danger comes from those who look like they belong to the flock. "Sheep's clothing" is the costume of the orthodox, the disguise of the pious. They use our vocabulary. They sing our hymns. They look, for all the world, like one of us. But this external appearance is a deliberate deception. Inwardly, in their essential nature, they are not sheep at all. They are ravenous wolves. A wolf does not come into the flock to help; it comes to devour. The motive of the false prophet is not the glory of God or the good of the sheep, but rather their own self-interest, be it money, power, sex, or the satisfaction of a destructive ego. Their goal is to consume, to take, to destroy.

16 You will know them by their fruits. Are grapes gathered from thorn bushes or figs from thistles?

Here is the diagnostic tool. The verb is future tense and emphatic: You will know them. This is not a suggestion; it is a promise. Despite the cleverness of the disguise, their true nature cannot be permanently concealed. It will manifest itself in their "fruits." Now, what are these fruits? It is a mistake to limit this to just one thing. Fruit is the total output of a life. It includes their doctrine, to be sure, but it is much more than that. It is their character, their conduct, the spirit of their ministry, their financial dealings, their family life, the effect they have on their followers. Jesus then gives two self-evident illustrations from the world of botany. You don't go to a thorn bush expecting to find grapes. You don't try to harvest figs from a patch of thistles. Everyone knows this. The principle is that a plant produces according to its kind. The outward product reveals the inward nature.

17 Even so, every good tree bears good fruit, but the bad tree bears bad fruit.

Jesus now states the principle plainly and universally. The word every is crucial. There are no exceptions. A good tree, one that is healthy and alive, will necessarily and consistently bear good fruit. This is what it does. It is its nature. Conversely, a bad tree, a corrupt or diseased tree, will necessarily bear bad fruit. The character of the fruit corresponds directly to the character of the tree. A man's life is the overflow of his heart. A good man, out of the good treasure of his heart, brings forth good things. An evil man, out of his evil treasure, brings forth evil things. The connection is absolute.

18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit.

To make sure we do not miss the point, Jesus states the same truth again, but this time in the negative, showing the impossibility of the alternative. A good tree cannot produce bad fruit. It is against its nature. An apple tree cannot, by some strange fluke, produce a crop of poisonous berries. Likewise, a bad tree cannot produce good fruit. A wolf in sheep's clothing might be able to glue a few pieces of wool to his hide, but he cannot bleat. He will eventually howl. He might manage a few isolated acts that appear good, but the consistent, settled pattern of his life, the "crop" that he yields, will be corrupt because he is corrupt. True, lasting, genuine goodness is the result of a regenerated nature, a new heart given by God. It cannot be faked.

19 Every tree that does not bear good fruit is cut down and thrown into the fire.

The stakes are now raised to their ultimate height. This is not merely a matter of agricultural classification; it is a matter of eternal destiny. The language here echoes John the Baptist's preaching: "the axe is already laid at the root of the trees" (Matt 3:10). The ultimate test for any tree in God's orchard is its fruitfulness. A tree that does not produce good fruit is not just useless; it is fuel. Its destiny is to be cut down and thrown into the fire. This is the fire of divine judgment. Notice the criterion: it is not the presence of bad fruit, but the absence of good fruit. The issue is unproductiveness, barrenness. In God's economy, there is no neutrality. A life that is not fruitful for God is by definition a "bad tree" destined for judgment.

20 So then, you will know them by their fruits.

Jesus concludes by repeating the foundational principle from verse 16, bookending the entire thought. The "so then" or "therefore" makes it a firm conclusion. This is the takeaway. This is the test you are to apply. Do not be taken in by the sheep's clothing of their words, their professions, or their outward piety. Stand back and look at the whole of their life. Look at the crop. What is the actual, tangible, observable product of their life and ministry? Is it the fruit of the Spirit: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control? Or is it the fruit of the flesh: discord, jealousy, fits of anger, selfish ambition, dissensions, factions? The tree is what the tree does.

Application

This passage is a divine mandate for every Christian to be a fruit inspector. This is not the same thing as being a fault-finder. A judgmental spirit, which Jesus condemns at the beginning of this chapter, is one that sets itself up as the standard and condemns others hypocritically. Fruit inspection, on the other hand, is a sober and necessary act of discernment, using God's revealed standard to protect the flock of God.

We must apply this test first to ourselves. What kind of fruit is my life producing? If I am honest, I will see a mixture. But what is the defining characteristic? What is the trend? Is the fruit of the Spirit growing, or is the produce of the flesh choking everything out? This passage should drive us to the gospel, because we know that on our own, we are all bad trees. The only way for a bad tree to produce good fruit is for God to perform a miracle of grace, to give us a new nature through faith in Christ. He cuts us out of the wild olive tree of Adam and grafts us into the cultivated olive tree of His Son (Rom 11). Only then, connected to Christ the true vine, can we bear much fruit.

Secondly, we must apply this to the teachers and leaders we listen to and follow. We live in an age of celebrity pastors and online prophets, where the sheep's clothing is more dazzling than ever. We must not be naive. We must not be impressed by charisma, or slick marketing, or large followings. We must be patient, careful fruit inspectors. Look at their character over time. Look at their families. Look at the kind of disciples their ministry produces. Are people being led to humility, holiness, and a deeper love for Christ and His church? Or are they being led into arrogance, division, and a cult of personality? The wolves are out there, and they are hungry. But our Good Shepherd has not left us defenseless. He has given us His Spirit and His Word, and this simple, profound, agricultural test: you will know them by their fruits.