The Prophet and False Prophets
Israel is again cautioned against learning "to follow the abominations" of the people living in the land, including the practices of witchcraft, sorcery or divination (verses 9-14). In contrast to pagan soothsayers, Moses prophesies that God would eventually raise up a Prophet like himself, referring to the coming of Jesus Christ (verses Deuteronomy 18:15-19; see John 1:45; Acts 3:22-23). He makes clear that just as the words from God that he proclaimed were to be obeyed, so it would be with this future Prophet. And indeed, like Moses, Jesus came as an Announcer of God's law and as a Mediator of a covenant based on that law. In short, Christ's words were to be followed—whereas others who would falsely claim to be prophets would have to be rejected (Deuteronomy 18:20).
Christ would later confirm that many false prophets would come to deceive the many (compare Matthew 24:4-5, 11). Sadly, this problem has always persisted among God's people (2 Peter 2:1-3). Moses gives a clue as to how to determine whether a person is a prophet of God or not: "When a prophet speaks in the name of the Lord, if the thing does not happen or come to pass, that is the thing which the Lord has not spoken; the prophet has spoken it presumptuously" (Deuteronomy 18:22). But one word of caution here: Sometimes, false prophets will foretell the future accurately (see Deuteronomy 13:1-5)—and God Himself may even be behind it (see Numbers 22:20, Numbers 22:38; Numbers 23:12). Yet even if someone relays many correct prophecies, the verse quoted above basically tells us that if there is just one instance where he claims that God has, apart from Scripture, specially and directly communicated to his mind regarding some event that will happen and the event does not come to pass as he proclaimed it would, that alone would make him a false prophet—that is, unless the proclamation is a warning of divine punishment and those to whom it is directed repent, as all such prophecies are contingent upon whether the recipients repent or not (compare Jeremiah 18:6-8; Jonah 3:1-10). And, of course, as explained in the highlights for Deuteronomy 13, someone's fulfilled prophecies are to be measured against his teachings and deeds. We are never to follow anyone's anti-biblical teachings or evil practices.