sectary

n.;pl. Sectaries [ F. sectaire. See Sect. ] A sectarian; a member or adherent of a sect; a follower or disciple of some particular teacher in philosophy or religion; one who separates from an established church; a dissenter. [ 1913 Webster ]

I never knew that time in England when men of truest religion were not counted sectaries. Milton. [ 1913 Webster ]