Heresy

From a Greek word for sub-group or sect.

Beliefs that are forbidden by the policy-deciding body of a faith group - a deliberate deviation from the orthodox doctrine.

Heresy is a relative term, because one group's heresy is frequently another group's required belief or dogma, and vice-versa. Heresies are inevitable in religion because there does not appear to be any mechanism by which religious disagreements can be resolved; either through reason or by assessing the will of God.