Jesus said to watch out for false teachers and to judge them by their fruit. How are we supposed to do this?
Jesus discussed judging fruits of teachers:
Matt 7:15 “Beware of false prophets who come disguised as harmless sheep but are really vicious wolves. 16 You can identify them by their fruit, that is, by the way they act. Can you pick grapes from thornbushes, or figs from thistles? 17 A good tree produces good fruit, and a bad tree produces bad fruit. 18 A good tree can’t produce bad fruit, and a bad tree can’t produce good fruit. 19 So every tree that does not produce good fruit is chopped down and thrown into the fire. 20 Yes, just as you can identify a tree by its fruit, so you can identify people by their actions.
What is bad fruit vs good fruit? Galatians 5:19-23 defines the fruits of the spirit vs the fruits of the flesh.
Gal 5:19 (NLT) When you follow the desires of your sinful nature, the results are very clear: sexual immorality, impurity, lustful pleasures, 20 idolatry, sorcery, hostility, quarreling, jealousy, outbursts of anger, selfish ambition, dissension, division, 21 envy, drunkenness, wild parties, and other sins like these. Let me tell you again, as I have before, that anyone living that sort of life will not inherit the Kingdom of God. 22 But the Holy Spirit produces this kind of fruit in our lives: love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, and self-control. There is no law against these things!
The fruit analogy is carried forward in Gal 6:7-8 with the theme of sowing and harvest:
Gal 6:7 Don’t be misled—you cannot mock the justice of God. You will always harvest what you plant. 8 Those who live only to satisfy their own sinful nature will harvest decay and death from that sinful nature. But those who live to please the Spirit will harvest everlasting life from the Spirit. 9 So let’s not get tired of doing what is good. At just the right time we will reap a harvest of blessing if we don’t give up. 10 Therefore, whenever we have the opportunity, we should do good to everyone—especially to those in the family of faith.
So how do we judge good vs bad fruit, is it exclusively based on behavior? No, it’s more complicated than this, behavior is just the first measuring stick. Obviously, anyone teaching sinful ideologies or promoting bad behavior is not producing good fruit, so that person is a false teacher according to the bible. However, people can seem like a good person based on behavior and still have wicked intentions, even Satan can “come as an angel of light” (2 Corinthians 11:14) . Instead, the focus should be what they are teaching. This means evil people can be cunning and manipulative using good deeds to masquerade false teaching about God, think of scammers and con artists sound nice in order luring a victim into a trap. When correcting the Pharisees about their abuse of Sabbath laws, Jesus said to judge things righteously, not by appearances (John 7:24). Which means righteous judgment goes beneath the surface. Jesus even says so in Matt 10:16 when warns the disciples to be “as shrewd as snakes and harmless as doves” because he sends them out “as sheep among wolves”. This means his disciples not be gullible and should judge things by the spirit, and not their flesh.
How do we judge things by the spirit?
Seed, time, and harvest. People and the things they teach won’t always be immediately recognized as good or bad. Fruit takes time to come from a seed. Jesus’ parable of the Wheat/Weeds (Matt 13:24), and its explanation (Matt 13:36-43) reveal this concept. In the parable, there is a farmer that planted wheat but then at night his enemy came and planted weeds. The servants ask the landowner about removing the weeds immediately, however, the farmer says they must wait until harvest time or else they will dig up the weeds with them because they look similar in immaturity. At harvest time the wheat and weeds are separated, the wheat is sorted in the barns and the weeds are burned. The point of the parable is that God won’t judge everyone immediately but waits until judgment day. Likewise, we should wait until the seeds mature so we can see them clearly before we can judge a person’s fruit.
John reminds us to test the spirits behind a person’s teachings as well:
1 John 4:1 Dear friends, do not believe everyone who claims to speak by the Spirit. You must test them to see if the spirit they have comes from God. For there are many false prophets in the world. 2 This is how we know if they have the Spirit of God: If a person claiming to be a prophet acknowledges that Jesus Christ came in a real body, that person has the Spirit of God. 3 But if someone claims to be a prophet and does not acknowledge the truth about Jesus, that person is not from God. Such a person has the spirit of the Antichrist, which you heard is coming into the world and indeed is already here. 4 But you belong to God, my dear children. You have already won a victory over those people, because the Spirit who lives in you is greater than the spirit who lives in the world. 5 Those people belong to this world, so they speak from the world’s viewpoint, and the world listens to them. 6 But we belong to God, and those who know God listen to us. If they do not belong to God, they do not listen to us. That is how we know if someone has the Spirit of truth or the spirit of deception.
In Deut 13:1-5 and Deut 18:15-22, God warns the Israelites about false prophets. Here he warns them about two kinds those that just lie in God’s name and those that even use false miracles to deceive but then teaches sinful actions like idolatry.
Deut 18:21 “But you may wonder, ‘How will we know whether or not a prophecy is from the Lord?’ 22 If the prophet speaks in the Lord’s name but his prediction does not happen or come true, you will know that the Lord did not give that message. That prophet has spoken without my authority and need not be feared.
Deut 13:1“Suppose there are prophets among you or those who dream dreams about the future, and they promise you signs or miracles, 2 and the predicted signs or miracles occur. If they then say, ‘Come, let us worship other gods’—gods you have not known before— 3 do not listen to them. The Lord your God is testing you to see if you truly love him with all your heart and soul. 4 Serve only the Lord your God and fear him alone. Obey his commands, listen to his voice, and cling to him. 5 The false prophets or visionaries who try to lead you astray must be put to death, for they encourage rebellion against the Lord your God, who redeemed you from slavery and brought you out of the land of Egypt. Since they try to lead you astray from the way the Lord your God commanded you to live, you must put them to death. In this way you will purge the evil from among you.
In Revelation 13, there are two figures described as “beasts” prophesied to emerge in the future, the false prophet and the antichrist, and they will deceive the masses with their teaching. The preceding scriptures are there to warn us to avoid people that teach things contrary to God’s word and that blaspheme and rebel against the true God.
Rev 13:1 Then I saw a beast rising up out of the sea. It had seven heads and ten horns, with ten crowns on its horns. And written on each head were names that blasphemed God. 2 This beast looked like a leopard, but it had the feet of a bear and the mouth of a lion! And the dragon [Satan] gave the beast his own power and throne and great authority. 3 I saw that one of the heads of the beast seemed wounded beyond recovery—but the fatal wound was healed! The whole world marveled at this miracle and gave allegiance to the beast. 4 They worshiped the dragon for giving the beast such power, and they also worshiped the beast. “Who is as great as the beast?” they exclaimed. “Who is able to fight against him?” 5 Then the beast was allowed to speak great blasphemies against God. And he was given authority to do whatever he wanted for forty-two months. 6 And he spoke terrible words of blasphemy against God, slandering his name and his dwelling—that is, those who dwell in heaven.7 And the beast was allowed to wage war against God’s holy people and to conquer them. And he was given authority to rule over every tribe and people and language and nation.
Rev 13: 11 Then I saw another beast come up out of the earth. He had two horns like those of a lamb, but he spoke with the voice of a dragon. 12 He exercised all the authority of the first beast. And he required all the earth and its people to worship the first beast, whose fatal wound had been healed. 13 He did astounding miracles, even making fire flash down to earth from the sky while everyone was watching. 14 And with all the miracles he was allowed to perform on behalf of the first beast, he deceived all the people who belong to this world. He ordered the people to make a great statue of the first beast, who was fatally wounded and then came back to life. 15 He was then permitted to give life to this statue so that it could speak. Then the statue of the beast commanded that anyone refusing to worship it must die. 16 He required everyone—small and great, rich and poor, free and slave—to be given a mark on the right hand or on the forehead. 17 And no one could buy or sell anything without that mark, which was either the name of the beast or the number representing his name. 18 Wisdom is needed here. Let the one with understanding solve the meaning of the number of the beast, for it is the number of a man. His number is 666.
The point is to watch what some preacher or priest is teaching and fact-check it against God’s word. If there is a conflict then believers in Christ can reject it and that warn others about those teachings, however, we must remember not to rush judgment because we may be wrong. Believers must take the time to truly investigate a cause because rejecting it before understanding it is foolish (Proverbs 18:13). We should wait and see how it affects the people who believe it and if causing them to follow God’s spirit and live the way God teaches or if it causes strife, immorality, and foolish actions.