“Stay alert because of false prophets, who come to you in sheep’s clothing yet inwardly are plundering wolves. From their fruits you will know them. Are grapes gleaned from thorn bushes or figs from thistles? Thus, every good tree makes excellent fruit, so the worthless tree makes evil fruit. It is not possible for a good tree to make evil fruit, nor for a worthless tree to make excellent fruit. Every tree not making excellent fruit is cut down and thrown into the fire. Thus, indeed, from their fruits you will know them.”
As already argued, there is a logical flow through these four warnings and thus a connected thread. This paragraph is tied to the previous section both logically and contextually. The destruction at the end of the broad path (v. 13) is contextually linked with the fire that consumes worthless trees (v. 19) and is likely a foreshadow of what Jesus means when He will demand that evildoers depart (v. 23). Logically, it seems that these false prophets are those who advocate for the wide gate and the broad way. Thus, the need to constantly remain vigilant and steer clear of them. With this second warning, Jesus’ conclusion gains intensity as He first warns of false guides (v. 15) and then explains how they might be exposed for who they truly are (vv. 16-20).
Exhortation for Vigilance (v. 15)
Jesus continues to address those who at least identify with Him. Yet, with each warning is attached implications that would expose any pretenders. While this warning explicitly confronts false leaders, teachers, and prophets, there remains an implication for those who would be wooed by them.
Who to Remain Vigilant For: False Prophets
“Stay alert because of false prophets.”
The present imperative from προσέχω (προσέχετε) literally means to “pay close attention”, “take heed”, or to “devote attention to”. The present tense indicates that this is to be obeyed immediately (start your vigilance!) and keep at it (remain alert!). The previous command emphasized the action itself (enter the narrow gate!). Here, Jesus expresses the need for immediate and continued vigilance.
He identifies false prophets (ψευδοπροφήτης) as the object of vigilance. A pseudo prophet (ψευδο-προφήτης) is akin to a pseudo apostle (2 Cor. 11:13), pseudo brother (2 Cor. 11:26; Gal. 2:4), or a pseudo teacher (2 Pet. 2:1) in that they are false, a sham, and not at all what they claim to be. A prophet (προφήτης/נָבִיא) is one who speaks for God in either oral or written form. What they say and what they write does not consist of their own words or interpretations but is an exact representation of what God has said. A false prophet is thus one who claims to speak for God but in fact does not.
Within the context of the SM we might be able to get more specific. The body of the sermon revolves around Jesus’ exposition of the Law and the Prophets (5:20; 7:12), thus linking Jesus as a prophet. Because this sermon condenses all that the Law and the Prophet’s teach (7:12), a false prophet is more specifically identified with anyone who teaches contrarily to what Jesus has claimed. Jesus has unambiguously stated that there are only two gates and only two roads. As such, He has demanded that His followers enter through the narrow gate and proceed down the pressed road to life. There will come those who will challenge and/or attempt to alter Jesus’ statement. Disciples must be on constant alert for such false prophets.
Why Remain Vigilant
“Who come to you in sheep’s clothing yet inwardly are plundering wolves.”
To emphasize the command to remain vigilant, Jesus provides three reasons why His followers must stay alert for these false teachers. First, Jesus identifies them as those who “come to you” (οἵτινες ἔρχονται πρὸς ὑμᾶς). False prophets are not appointed by God but are self-appointed. They are not recognized from within the assembly but approach from the outside. If it were not so, there would be no reason to remain vigilant.
Next, Jesus emphasizes the fact that they appear as harmless individuals. They come wearing sheep’s clothing. “Sheep’s clothing” is an accurate representation of the Greek (ἐνδύμασιν προβάτων) and does not indicate clothing made of wool nor a sheepskin mantle. They are dressed as a sheep is dressed and thus appear to be a sheep. The idea is that they have all the appearance of harmlessness because they have put on an external façade of belonging to the flock, a common illustration of God’s people Israel (Is. 40:11; Jer. 23:2-3; 50:17; Ezek. 34:1-31; Mic. 2:12; 5:1-4; Zech. 9:16; Ps. 23:1; 78:71; 80:1). They have disguised themselves in order to infiltrate the covenant community. Thus, vigilance is required.
Finally, these disguised infiltrators pose a serious threat. Though they appear to be sheep, inwardly they are plundering wolves. A wolf is not only the antithesis of harmless but is the natural enemy of the sheep. To let a wolf into the flock is to allow the destruction of them all. Jesus’ words are remarkably similar to that of the prophet Ezekiel when he recorded Yhwh’s description of Israel’s prophets, priests, and princes (Ezek. 22:23-31). Those who were supposedly members, leaders, and protectors of the people were in fact predators seeking to exploit the people by any means necessary. If this is the text Jesus has in mind (and it seems likely) then these wolves may be even more devious due to the fact that the social, political, and religious status identify them as men who should be trusted. That Jesus has in mind the scribes and Pharisees is almost without question, yet it would be a mistake to limit Jesus’ illustration to only them. These wolves are any and all who proclaim error for personal gain.
Jesus describes these wolves as plundering (ἅρπαξ). The adjective describes a robber or rogue, normally translated as swindler (Lk. 18:11; 1 Cor. 5:10, 11; 6:10). The point is that they take all they can get through deception. The form of deception has already been identified: their sheep-like appearance. In keeping with the illustration, one is forced to ask: what would a wolf take from sheep? The answer: their very lives! The point is not to suggest that these false prophets are in fact serial killers. But if they advocate anything conflicting to Jesus’ narrow gate and pressed way, they advocate destruction in opposition to life. Not only are they contrary, cunning, and camouflaged, they are bent on carnage. Obviously, disciples must remain alert for such threats to the flock. If they are so well concealed, how are disciples to unmask them? Jesus reveals how this is done in the following verses.
Explanation to Expose False Prophets (vv. 16-20)
Jesus’ plan of how to pierce the sheeplike façade and expose false prophets for who they really are is simple, elegant, and profound. The careful reader should note that the means of revealing their character (from their fruits…) introduces and concludes this section and thus forms an inclusio. From this inclusio, a chiastic-like structure begins to emerge:
Test Stated (v. 16a)
“From their fruits you will know them.”
Most of our English translations miss the fact that “by their fruits” (ἀπὸ τῶν καρπῶν αὐτῶν) is placed forward of the main statement “you will know them” (ἐπιγνώσεσθε αὐτούς). By fronting the prepositional phrase, Jesus emphasizes the means by which disciples might identify these shadowy wolves. It is impossible to recognize them based on external looks, for they wear the clothing of sheep and thereby pass unnoticed by appearance. Only by examining their fruit can disciples discern their inward wolfish nature.
There is much debate around what is meant by “fruits”. One camp strongly emphasizes their works over their words, insisting that they may talk a good game, but their behavior will reveal. The other camp insists that it is their very words, that is, what they teach which will expose their large eyes, pointy nose, and sharp teeth. While we are again forced to admit that Jesus does not expressly state what “fruit” designates in these verses, He has provided sufficient clues within the context to grasp His meaning.
First, we must consider what a false prophet is and what he does. As already stated, a false prophet claims to speak for God when in fact he does not. Therefore, it would be foolish to think his “fruit” as something other than what he says, claims, and teaches. A false prophet prophesies falsely. He is a false prophet by virtue of his contrary content. This contrary content contradicts Jesus’ own teaching. The climax of Jesus’ conclusion found in vv. 24-27 emphasizes Jesus’ own words (who hears these words of mine…). Thus, the chief component of their fruit is the consistency of their teaching with that of Jesus’.
Second, there is also included a sense of what they do. The verb ποιέω (to do, make, produce) appears five times in these six verses, always referring to the production of this fruit. Likewise, Jesus does not limit His true disciples as those who only hear His words (and thus teach them) but demands that they are also those who do (ποιέω) them (v. 24). Thus, we can safely say that while the emphasis is placed on the content of teaching, there is included the idea of obedience. “Fruit” is therefore defined for us by Jesus as both content and conduct. Wolves will be known by what they say and how they live.
Test’s Rationale (v. 16b)
“Are grapes gleaned from thorn bushes or figs from thistles?”
This statement introduces Jesus’ rationale: wholesome fruit is not found on worthless plants. The question is rhetorical, the answer to which is obviously negative (μήτι). Both grapes and figs are wholesome and useful fruit, a normal staple in the ancient Levant grown in cultivated orchards and vineyards. Thorns and thistles are indicative of untended, uncultivated wilderness. One does not leave the garden to seek fruit in the wilderness. The sheer ridiculousness of this question betrays Jesus’ sarcastic humor while pressing home His point. If one does not seek among the thorns for grapes or search for figs on thistles, why would one expect to find worthwhile sustenance from those who teach and live contrarily to Jesus’ words? As products of the curse (Gen. 3:18), thorns and thistles cannot possibly produce wholesome fruit.
Test’s Affirmation (vv. 17-18)
“Thus, every good tree makes excellent fruit, so the worthless tree makes evil fruit. It is not possible for a good tree to make evil fruit, nor for a worthless tree to make excellent fruit.”
Jesus now presses the image of fruit bearing plants further to prove that the wholesomeness of the fruit corresponds with the kind of tree it comes from. He does so first positively (v. 17) and then negatively (v. 18).
Most English translations miss the fact that Jesus uses different adjectives to describe the trees and their fruit. Good (ἀγαθός) trees make excellent (καλός) fruit while worthless (σαπρός) trees make evil (πονηρός) fruit. What is the significance of these various adjectives? Our first task is to discover the precise meaning of ἀγαθός (the good tree) by comparing it with σαπρός (the bad tree). While normally translated simply as good, ἀγαθός describes the high standard, quality, or worth of an object. The good tree could therefore be understood as being useful/beneficial (a productive tree/that which produces useful fruit) or valuable (a costly tree). This tree is compared to the bad tree (σαπρός). This adjective is truly an antonym of ἀγαθός as it describes something of poor quality or lacking in value. The image is therefore of a useful tree that is beneficial and that of a worthless tree that offers nothing of value.
A similar comparison of the fruit will show that καλός also describes the high quality of an object (good) yet it surpasses ἀγαθός in that it describes the intrinsic quality of an objects substance. The tree is good (ἀγαθός) because it produces and is therefore useful and beneficial. The fruit is good (καλός) by virtue of what it is. If the tree ceases to produce, it is no longer good (ἀγαθός). On the other hand, the fruit will never cease to be good (καλός). The tree is good because of what it does. The fruit is good because of what it is. The other fruit is likewise described by its intrinsic nature. Πονηρός describes something that is utterly without worth in either a moral (evil, wicked), social (base, degenerate), or physical (worthless) sense. The fruit of the worthless tree is evil by virtue of what it is.
At this point, two things are worthy of note. First, we cannot fail to recognize that this language is taken directly out of Genesis and Moses’ description of the garden. The LXX consistently uses καλός (that which is intrinsically good) to describe creation (Gen. 1:4, 8, 10, 12, 18, 21, 25, 31). Likewise, the very first time καλός (good) and πονηρός (evil) are used together (in fact, the very first time πονηρός appears at all) is in the description of the tree of the knowledge of good and evil (Gen. 2:9). Not only is Jesus’ metaphor very garden-like, but His vocabulary presses home the emphasis of there only being two sides to choose from. These false prophets are not simply contrary to Jesus but are in fact servants of the serpent.
Second, both trees, the good and the bad, are described as such because of the fruit which they produce. The usefulness of the first tree and the worthlessness of the second are directly associated with the fruit they produce. The nature of the fruit cannot be changed. Yet, if a “good” tree suddenly began producing evil fruit, it would no longer be a good tree at all. Likewise, if a “bad” tree began sprouting excellent fruit, it would no longer be considered worthless. Yet, as Jesus goes on to make clear, such a phenomenon is impossible.
In v. 18 Jesus reiterates the connection between the trees and their fruit in a negative fashion, that is, He states the utter impossibility of inverting the paradigm. A useful and beneficial tree cannot produce evil fruit. Such intrinsically evil fruit would by definition make the tree worthless and good for nothing. Likewise, if a worthless tree produced excellent and beautiful fruit, it could never be considered as worthless. The fruit is what designates the tree as either being beneficial or worthless. It is for this reason that Jesus exhorts His disciples to discern their fruit, for the fruit will tell all.
Test’s Result’s (v. 19)
“Every tree not making excellent fruit is cut down and thrown into the fire.”
If a tree is not beneficial, but is in fact worthless by producing evil fruit, then why does it remain to soak up nutrients and take up space needed by useful trees? Jesus plainly states that this will not always be the case. Every single worthless tree will be removed and destroyed. Within the context of the metaphor, the fire is quite literal and yet it adds a connective tie to the eschatological destruction of v. 13 as well as the judgment pronounced by Jesus Himself of those who are barred from entering His kingdom (v. 23). In addition to this obvious fact we must include two observations.
First, this statement repeats verbatim what John the Baptist said to the Pharisees and Sadducees (3:10). More than prove that Jesus and John preached the same kingdom by the same means, this is a subtle affirmation by Jesus that John was a true prophet. What John said and how he conducted himself corresponds perfectly with Jesus’ teaching here. His audience would certainly have recognized this and thus John’s call to repentance is affirmed as a word from God. From his outward appearance, John was rough and wild (3:4). Hardly the covert type attempting to pass unnoticed with the crowd. Yet his content and conduct mark him as a tree bearing excellent fruit. The implication is obvious: listen to him!
In addition to this, we should recognize that it is not due to what the worthless tree does, but according to what it fails to do that leads to its destruction. Every tree that fails to produce excellent fruit is cast into the fire. Those who teach less error than others are not safe. Those who live less wickedly than others are not safe. The standard is not a sliding scale of evil but is rather complete fidelity to Jesus in word and deed.
Test Re-Stated (v. 20)
“Thus, indeed, from their fruits you will know them.”
Jesus repeats His initial test as a perfect inclusio to this section. The inferential conjunction ἅρα (thus) draws on the entire section while the particle γέ (indeed/surely) emphasizes the point. False prophets will work overtime to avoid detection. Their wolfish character and appetites are dangerous to the flock of God and thus they cannot be allowed into the fold. Thus, the need for disciples to remain vigilant. Yet, in their vigilance, there is no reason to fear. Wolves are clever, but they are not invisible. Their fruits (their content and conduct) will expose them. Disciples who know Jesus’ teaching and obey it (v. 24) should have little trouble identifying these predators. While it is true that they desire to pillage and plunder the sheep, there is still no need to fear nor to exercise independent judgment on them. They will be cut down and thrown into the fire. God will judge them rightly and thoroughly in the end. The warning is therefore to remain alert to identify and avoid, not confront or combat. Jesus will handle those who refuse to submit to Him in word and deed. As for disciples, their duty is plain: Follow Jesus alone.
 John Nolland, The Gospel of Matthew, The New International Greek Testament Commentary (Grand Rapids, MI: Eerdmans Publishing Company, 2005), p. 338.
 With nearly 90% of the populace dressed in either wool, linen, or (most commonly) a combination thereof (a linen tunic under a woolen cloak), this woolen theory does nothing to identify those who are false teachers. A truly laughable interpretation.
 Hendriksen, p. 372.
 David Garland, Reading Matthew: A Literary and Theological Commentary on the First Gospel (New York, NY: The Crossroad Publishing Company, 1993), p. 88-9.
 R. C. H. Lenski, The Interpretation of St. Matthew’s Gospel (Minneapolis, MN: Augsburg Publishing House, 1961), p. 301.
 Leon Morris, The Gospel According to Matthew, The Pillar New Testament Commentary (Grand Rapids, MI: Eerdmans Publishing Company, 1992), p. 179.