What are some signs of false teachers?

from the old testament

• The Old Testament establishes the foundation for recognizing false teachers by laying out God’s standards for true prophecy. In Deuteronomy 13:1–5, Israel was warned not to follow prophets who performed signs but, nevertheless, encouraged worship of other gods. Even if predictions seemed to come true, the decisive test was fidelity to the LORD. True teaching always directed people to loyalty to God, while false teaching led them away.
• Another test is given in Deuteronomy 18:20–22. It reads, “the prophet who presumes to speak a word in my name that I have not commanded him to speak, or who speaks in the name of other gods, that same prophet shall die. And if you say in your heart, ‘How may we know the word that the LORD has not spoken?’—when a prophet speaks in the name of the LORD, if the word does not come to pass or come true, that is a word that the LORD has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.” In other words, a prophet whose prophecy did not come true was proven to be a false prophet.
• As an example, Jeremiah dealt with prophets who assured Judah that judgment was not coming, saying “peace, peace” when there would be no peace (Jeremiah 6:14). These prophets appealed to what people wanted to hear, avoiding confrontation with sin. This is often the case with false teachers—they want people to think highly of them.
• Ezekiel described a similar problem: “Woe to the foolish prophets who follow their own spirit, and have seen nothing! …. They have seen false visions and lying divinations. They say, ‘Declares the LORD,’ when the LORD has not sent them, and yet they expect him to fulfill their word. Have you not seen a false vision and uttered a lying divination, whenever you have said, ‘Declares the LORD,’ although I have not spoken?” (Ezekiel 13:3, 6–7). They were whitewashing Israel’s sin, offering visions from their imaginations, giving the people false confidence.
• Not only could one tell a prophet was a false prophet by their false prophecies, but their moral character could also give them away. Speaking about Israel’s sin in general, God said, “Its heads give judgment for a bribe; its priests teach for a price; its prophets practice divination for money” (Micah 3:9-11). In effect, all of Israel’s leaders—including the spiritual ones—operated on the basis of how much money they could get, not caring whether or not God was glorified.
• Together, these Old Testament passages show that false prophets were defined by two traits: the distortion of God’s Word, and self-serving lives. Prophets in the Old Testament were the primary teachers of God’s Word, so it’s not surprising to learn that false teachers today have very similar characteristics of the Old Testament false prophets.

from the new testament

• Jesus warned that false teachers would come, appearing “in sheep’s clothing but inwardly are ravenous wolves” (Matthew 7:15). What He was saying was that false teachers outwardly appear to be like the rest of the flock. However, despite that appearance, Jesus said they are to be tested to see what’s inside of them. He said, “You will recognize them by their fruits. …. every healthy tree bears good fruit, but the diseased tree bears bad fruit. …. Thus you will recognize them by their fruits” (Matthew 7:16a, 17, 20). A teacher who is a true Christian will bear godly fruit, but a false teacher’s fruit will be rotten. Jesus was saying to look past their demeanor or personality and to see whether or not they were producing the type of fruit that comes from the Spirit (cf., Galatians 5:22–24).
• Paul also consistently warned churches to beware of those who distort the gospel. In his day, there was a group of individuals who were preaching a gospel that included strict obedience to the Mosaic law (Galatians 2:4). Writing to the Galatians, a group of believers particularly being led astray by this teaching, he wrote, “even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed” (Galatians 1:8). It doesn’t matter who the person is, if he or she is teaching any other way to be saved than what the Bible teaches, then that is a clear sign that they are a false teacher.
• Peter gave a detailed portrait of false teachers in 2 Peter 2. Notice how he links the Old Testament false prophets with the New Testament false teachers: “false prophets also arose among the people, just as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Master who bought them, bringing upon themselves swift destruction. And many will follow their sensuality, and because of them the way of truth will be blasphemed. And in their greed they will exploit you with false words. Their condemnation from long ago is not idle, and their destruction is not asleep” (2 Peter 2:1–3). In short, he describes false prophets and false teachers as greedy, sensual, arrogant, and exploitative. Jude likewise noted that they “pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ” (Jude 4). Both individuals emphasized that false teaching leads to both doctrinal error and moral corruption.
• John, for his part, urged his readers to “test the spirits to see whether they are from God, for many false prophets have gone out into the world” (1 John 4:1). The test was to see whether the teachers to whom they were listening confessed the true Jesus Christ (and, thus, the true gospel) or whether their teaching diverged at all.
• In summary, the New Testament shows that false teachers are marked by distorted doctrine and ungodly character, having divisive or greedy motives. Believers are told to not take everyone at face value, but test what they are taught with Scripture (Acts 17:10–11) so that they remain rooted in Christ and His gospel.

implications for today

False teaching continues through to today wherever the gospel is twisted for popularity, profit, or power. Some false teachers today promise material prosperity in exchange for faith, while others downplay sin or deny Christ’s deity. What unites them is a message that diverges from the gospel of grace as revealed in Scripture.

Because of this reality, believers are called to be discerning. You do not need to be an expert in every heresy to do this. It is often said that the way a bank teller detects a forged bill is not by learning every counterfeiting trick but by handling real bills all day long. When a fake one comes through their hands, they sense it because they know it’s different than the others they have handled. Likewise, as a believer, you should be handling the truth (the Bible) every day so that when you come across a false teacher, you “feel” the difference. You may not always be able to articulate what’s wrong with his or her teaching, but that sense that things are not quite right will be a key sign to stop and examine them more closely. Therefore, read God’s Word faithfully, test teaching by Scripture, and watch the fruit of those who lead. Do their words exalt Christ or themselves? Do their lives show holiness or hypocrisy?

At the same time, remember that your protection from error is not on your shoulders, alone. The Spirit of God dwells in you, guiding you into truth and keeping you from being ultimately deceived. Therefore, when you remain close to Christ, rooted in His Word, you can walk in confidence, knowing that He will preserve you from falsehood and keep you in the truth that leads to life.