Deuteronomy 18 Test
The Deuteronomy 18 Test is one of several tests found in the Bible to distinguish between true and false teachers or prophets (as well as between true and false teachings). There are two aspects of the Deuteronomy 18 Test. The first aspect is this: Anyone who speaks a prophesy in God's name which does not come true is a false prophet. The second aspect is this: Anyone speaking in the name of a different God is a false prophet or teacher. A person should be tested against Deuteronomy 18 first. Only after the person passes this test can that person then be tested against Deuteronomy 13.
"But a prophet who presumes to speak in my name anything I have not commanded, or a prophet who speaks in the name of other gods, is to be put to death." [Deuteronomy 18:20; NIV]
"You may say to yourselves, 'How can we know when a message has not been spoken by the Lord?' If what a prophet proclaims in the name of the Lord does not take place or come true, that is a message the Lord has not spoken. That prophet has spoken presumptuously, so do not be alarmed." [Deuteronomy 18:21-22; NIV]