False prophets and teachers present the greatest threat to the church of Jesus Christ. External enemies who brazenly attack God’s people are easy to identify, and their threat is simpler to discern and resist. Internal enemies, however, are not dealt with so easily. Wolves can go about in sheep’s clothing for a long time before they are finally found out. False teachers, because they come in Christ’s name, elicit the trust of their students, and their corrupt doctrine weakens the faith of those who sit under their teaching.
Recognition of the threat of false teachers goes all the way back to the exodus generation, and Moses specifically warned the Israelites against those who would claim to be prophets while leading them to worship other gods. Deuteronomy 13:1–5 notes that the test of a true prophet is not his ability to perform signs and wonders; rather, true prophets are identified by their orthodoxy. In other words, no matter how convincing the signs and wonders of a professed prophet or teacher may be, that person must be rejected if he teaches heresy.
Moses’ principle remains true in every generation. It is true in ours, and it was true in the years leading up to the fall of Jerusalem in AD 70. Jesus warned that once the Romans invaded the city, many false teachers would implore them not to flee to the mountains. Instead, these preachers of error would try to deceive Christ’s disciples, calling them to follow after other people who professed to be the Messiah. Many of these false teachers, Jesus said, would “perform signs and wonders, to lead astray, if possible, the elect” (Mark 13:14–22).
Note the qualifier “if possible” in Mark 13:22. Jesus’ point was that the false signs would be so convincing that they could fool even God’s elect people; however, in the end the elect would not be convinced because no one can finally lead the elect astray. That is due to the preserving mercy of the Lord, not the strength of the elect. John Calvin comments: “However frail and slippery the condition of the godly may be, yet here is affirm footing on which they may stand; for it is not possible for them to fall away from salvation, to whom the Son of God is a faithful guardian. . . . The permanency of our salvation does not depend on us, but on the secret election of God.”
God preserves forever those He has elected to salvation. How do the elect reveal themselves? By believing in Christ and being on guard against all who oppose Him (Mark 13:23). For the elect are those who rest in Christ alone for salvation (Rom. 8:28–30).