Deuteronomy 18:17-22

So the LORD said to me, “What they have said is good. So I will give them a prophet like you, who is one of their own people. I will tell him what to say, and he will tell them everything I command. This prophet will speak for me; anyone who does not listen when he speaks will answer to me. But if a prophet says something I did not tell him to say as though he were speaking for me, or if a prophet speaks in the name of other gods, that prophet must be killed.” You might be thinking, “How can we know if a message is not from the LORD?” If what a prophet says in the name of the LORD does not happen, it is not the LORD’s message. That prophet was speaking his own ideas. Don’t be afraid of him.