You will know that, if the thing that he speaks about does not happen. If it does not happen, that message has not come from the Lord. He has not spoken it. That prophet has spoken his own message. Do not be afraid of him! Deuteronomy 18:22
先知託耶和華的名說話，所說的若不成就，也無效驗，這就是耶和華所未曾吩咐的，是那先知擅自說的，你不要怕他。」 申命記 18:22