Deuteronomy 18:20-22

Living Bible

²⁰ But any prophet who falsely claims that his message is from me shall die. And any prophet who claims to give a message from other gods must die.’ ²¹ If you wonder, ‘How shall we know whether the prophecy is from the Lord or not?’ ²² this is the way to know: If the thing he prophesies doesn’t happen, it is not the Lord who has given him the message; he has made it up himself. You have nothing to fear from him.