False prophet
From ReformedWiki.org, the wiki for Reformed Christianity
A false prophet is any person who claims to be a prophet and either lacks credibility or teaches unbiblical heresy.
The New Testament contains many verses which teach how to tell a false prophet from a true prophet (Matthew 7:15, 1 Corinthians 14:37, 2 Peter 2:1)
Some notable false prophets include the biblical "prophets of Baal" of Canaanite paganism, Simon Magnus the founder of Gnosticism, Muhammed the founder of Islamand Joseph Smith the founder of Mormonism.
