In religion, a false prophet is a person who falsely claims the gift of prophecy or divine inspiration, or to speak for God, or who makes such claims for evil ends. Often, someone who is considered a "true prophet" by some people is simultaneously considered a "false prophet" by others, even within the same religion as the "prophet" in question. In a wider sense, it is anyone who, without having it, claims a special connection to the deity and sets him or herself up as a source of spirituality, as an authority, preacher, or teacher. Analogously, the term is sometimes applied outside religion to describe someone who fervently promotes a theory that the speaker thinks is false.
Christianity
Christian eschatology originated with the public life and preaching of Jesus. Throughout the New Testament and some of the early Christian apocryphal writings, Jesus warns his disciples and apostles multiple times of both false prophets and false Messiahs, and believers are frequently adjured to beware of them and stay vigilant.
Gospels
In the Sermon on the Mount (Matthew ), Jesus warns his followers of false prophets:
"Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves. You will know them by their fruits. Are grapes gathered from thorns, or figs from thistles? So, every sound tree bears good fruit, but the bad tree bears evil fruit. A sound tree cannot bear evil fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will know them by their fruits."
The canonical gospels address the same point of a false prophet predicting correctly, and Jesus predicted the future appearance of false Christs and false prophets, affirming that they can perform great signs and miracles, for example, in the Olivet Discourse given on the Mount of Olives:
"And Jesus began to say to them, “Take heed that no one leads you astray. Many will come in my name, saying, I am he! and they will lead many astray. And when you hear of wars and rumors of wars, do not be alarmed; this must take place, but the end is not yet. [...] And then if any one says to you, Look, here is the Christ! or Look, there he is! do not believe it. False Christs and false prophets will arise and show signs and wonders, to lead astray, if possible, the elect. But take heed; I have told you all things beforehand”." (Mark , ) "Take heed that no one leads you astray. For many will come in my name, saying, I am the Christ, and they will lead many astray. [...] And many false prophets will arise and lead many astray. [...] Then if any one says to you, Lo, here is the Christ! or There he is!, do not believe it. For false Christs and false prophets will arise and show great signs and wonders, so as to lead astray, if possible, even the elect. Lo, I have told you beforehand. So, if they say to you, Lo, he is in the wilderness, do not go out; if they say, Lo, he is in the inner rooms, do not believe it." (Matthew , , )
In the Gospel of Luke, Jesus brought out an ethical application for his disciples using the analogy of false prophets in the Old Testament:
"Woe to you, when all men speak well of you, for so their fathers did to the false prophets." (Luke )
Acts and Epistles
In the Book of Acts, the apostles Paul and Barnabas encountered a false prophet named Elymas Bar-Jesus on the island of Cyprus:
"When they had gone through the whole island as far as Paphos, they came upon a certain magician, a Jewish false prophet, named Bar-Jesus. He was with the proconsul, Sergius Paulus, a man of intelligence, who summoned Barnabas and Saul and sought to hear the word of God. But Elymas the magician (for that is the meaning of his name) withstood them, seeking to turn away the proconsul from the faith. But Saul, who is also called Paul, filled with the Holy Spirit, looked intently at him and said, “You son of the devil, you enemy of all righteousness, full of all deceit and villainy, will you not stop making crooked the straight paths of the Lord? And now, behold, the hand of the Lord is upon you, and you shall be blind and unable to see the sun for a time.” Immediately mist and darkness fell upon him and he went about seeking people to lead him by the hand. Then the proconsul believed, when he saw what had occurred, for he was astonished at the teaching of the Lord." (Acts )