Mystery religion is a term used to describe various ancient religions, which had their beliefs, practices, and initiations kept secret from outsiders. These religions were called mystery religions because the knowledge of their doctrines was only accessible to members of the specific religious cults. Synonyms for mystery religions include cults, sects, esoteric religions, and secretive religions. These religions were practiced in secrecy and had initiations with deep spiritual meanings that only members could comprehend. They were characterized by initiation rites and their members were guided by a set of beliefs and principles, which were not shared with the general public. The secrecy that surrounded these religions added to their allure and made them an object of fascination for scholars and historians alike.