Deuteronomy 13

Moses addresses the extreme danger of false prophets and false teachers who might try to lure the people into idolatry, even if they perform signs or miracles. He commands that any prophet who suggests worshipping other gods, or even a close relative who secretly encourages idolatry, must be put to death. If an entire city turns to idolatry, it must be completely destroyed and burned, reinforcing the seriousness of maintaining absolute loyalty to the Lord alone.