[n] a person who has religious faith
[n] a supporter who accepts something as true
abiogenist, admirer, apostle, booster, champion, colonialist, Confucian, denomination, devil worshiper, friend, imperialist, Malthusian, monotheist, mystic, numerologist, pantheist, pilgrim, protagonist, religionist, religious mystic, religious person, sun worshiper, supporter, theist, theosophist, vitalist
1. One who believes; one who is persuaded of the truth or reality of some doctrine, person, or thing.
2. (Theol.) One who gives credit to the truth of the Scriptures, as a revelation from God; a Christian; -- in a more restricted sense, one who receives Christ as his Savior, and accepts the way of salvation unfolded in the gospel. Thou didst open the Kingdom of Heaven to all believers. --Book of Com. Prayer.
3. (Eccl. Hist.) One who was admitted to all the rights of divine worship and instructed in all the mysteries of the Christian religion, in distinction from a catechumen, or one yet under instruction.