False prophets tell people what they want to hear instead of calling them to obey God's will. Deuteronomy 13:1–5 and 18:21–22 provide guidelines to determine if someone is a true prophet. A prophet's words must match with God's word, and a prophet's prophecies must come true.
Jesus explains the first rule. A prophet's actions must match his words to be trustworthy. So, a true prophet's actions will also match God's word. In the same way that fruit shows what kind of tree it comes from, a person's life shows if their inner being is good or not.
Christians should expect false prophets at the end of time (see Matthew 24:11, 24; Acts 20:28–35; Revelation 13:11–18; 16:13; 19:20; 20:10). Christians can avoid these false prophets misleading them. But Christians must be careful and wise (see 1 Corinthians 12:10; 14:29; 1 Thessalonians 5:21; 1 John 4:1–3; Revelation 2:20).