(n.) One who engages earnestly warmly in any cause, especially, one who is overzealous, or carried away by his zeal\; one absorbed in devotion to anything; an enthusiast; a fanatical partisan.

Christian God-fearing man accepter addict adherent aficionado alien believer bigot buff bug case catechumen character churchgoer churchite churchman collector communicant convert crackpot crank daily communicant demon devotee devotionalist disciple eager beaver eccentric energumen enthusiast extremist faddist fan fanatic fanatico fiend follower freak good Christian great one for hermit hobbyist hobo hound infatuate kook lone wolf loner lunatic fringe maniac maverick meshuggenah militant monomaniac natural neophyte nonconformist nut odd fellow oddball oddity original outsider pariah partisan pietist proselyte pursuer queer duck queer fish queer specimen radical rara avis receiver religionist rhapsodist saint screwball sectary solitary sucker for theist tramp truster type visionary votary