An easy way to recognize a tree is by its fruit, as Jesus reminds you in Matthew 7:15–20.
Recognize a tree by its fruit. Beware of false prophets. The broad way is promoted by false teachers. False prophets are deceptive. They are like wolves in sheep’s wool. They appear harmless, or even beneficial, but their impact is devastating. They may come to you door appearing as sincere students of the Bible. They may enter your home through radio or television waves, claiming to preach Christ, but denying crucial aspects of the Word of God. They may be leaders in prominent religious groups. False prophets mute God’s message. They may be self-serving, see Matthew 23:1-4, 13ff. They may simply downplay the truth because it is unpopular, Jeremiah 8:11.
Look for good fruit. Evaluate, but don’t distrust all teaching. The warning alone might make you plug your ears to any teaching. Jesus provides a way of testing. “[N]othing is more difficult than to counterfeit virtue.” (John Calvin, Commentary on the Gospels). Look for fruit. You recognize a plant by its fruit. The principle applies to recognizing true teaching. Look for evidence in the prophet’s life. If he is a true prophet, there will be a life that seeks to obey the Lord. A life of rebellion is a sign of false prophecy. Test the message by the Word of God. If Luke could commend the Bereans for searching the Scriptures (Acts 17:11), you also need to evaluate what you hear–from this pulpit as well as from the TV, radio, and books. Look for fruit in your own life. You may not be a prophet, but the principle Jesus points to not only distinguishes true prophecy from false, it also identifies a true profession of trust in Christ (see v.21). Don’t merely ask yourself whether you claim to be a Christian, whether or not you have been baptized, whether or not you worship with God’s people. All of these are important. But also ask yourself if you are giving evidence of the fruit of the Spirit.
Remember that hypocrisy leads to judgment. Unfruitful trees are burned. Judgment comes on disobedience. False prophets may be popular and wealthy in this life, but they are playing a dangerous game. There are consequences to disobedience. Just as a farmer prunes the trees in his orchard, culls out unproductive ones, and burns them, so the Lord brings judgment on disobedience. Note that simply being unfruitful is grounds for condemnation. Just as Jesus shuts you up to a choice between two ways, one leading to life, the other to destruction, so he sets before you the choice of being fruitful or unfruitful. There is no neutral ground.
Judgment comes. The language of the axe and fire portray judgment. Note the words of John the Baptist, Matthew 3:7-12. John had prepared for the coming of the Messianic King, who would bring judgment. Now Jesus has appeared, but instead of sitting on the great white throne of judgment, he is sitting on the mountain, preaching to the people, Matthew 5:1. No, judgment has not been abandoned. It runs through Jesus’ preaching as much as truly as it does in John’s. Take seriously Jesus’ warnings.
Be a fruitful tree. What is different is the time frame. John apparently expected the Messiah to bring immediate judgment. But Jesus gives time for repentance, for faith, and for obedience. Jesus is giving you time to turn to him and to bear fruit. “Those who want to enter the kingdom must. . . return to the Father with a confession of sin (Luke 15:18), and go through the narrow gate and walk down the narrow path (Matt. 7:14). Those who really do this are enabled to do so b y God himself. For human beings are by nature evil (7:11). Out of their hearts come nothing but wickedness (15:19). Like a bad tree, they cannot produce good fruit (7:17ff.). Accordingly, if there is to be good fruit, the tree must be made good first, something only God can do (19:26).” (Herman Bavinck, Reformed Dogmatics, Vol. 4, p. 47). The only way that you can bear fruit is if you are a tree that is rooted in the Lord Jesus Christ. It is the citizens of the kingdom of heaven that are vindicated in the final judgment. Bearing fruit is not a matter of trying to do enough to earn God’s favor. You and I as sinners can never do enough to enter the kingdom of heaven. Bearing fruit, however, is a matter of being a tree that has roots deep in the ground, drawing water from the river of life. The trees in Eden were watered by the rivers the Lord channeled through Paradise. Psalm 1 compares the righteous to a tree planted by rivers of water. In Revelation the trees on either side of the river of life, flowing from God’s throne, bear fruit and the leaves are for the healing of the nations. Jesus is not only warning you against being a dried up, unproductive tree fit for burning. He is calling you to a living relationship with him. Fruit-bearing is not just something that you do. It is what you are, because you are rooted in Christ. “Righteousness must be fruit, the organic product of the life and character, exponential of what is within, Matt. 7:16, 20; 21:43.” (Geerhardus Vos, The Kingdom of God and the Church, p. 62). Jesus is calling you to be what you are.
Yes, look out for false prophets. Do ask yourself if you are bearing fruit. But do that as you put down roots and are connected with the One who is the source of life and fruitfulness—your Lord Jesus Christ.