Heretic - The term heretic describes individuals who dissented from the beliefs or practices of the controlling Christian religious authorities. This is different from the non-believer such as the Jew or Muslim who operated outside the Christian faith.

Someone who holds or adheres to an opinion or belief that contradicts established religious teaching, especially one that is officially condemned by religious authorities. Someone whose opinions, beliefs, or theories in any field are considered by others in that field to be extremely unconventional or unorthodox.

A person who holds religious beliefs in conflict with the dogma of the Roman Catholic Church.