Religionist

Re·li·gion·ist

Religionist

n.
  1. One earnestly devoted or attached to a religion; a religious zealot.
    The chief actors on one side were, and were to be, the Puritan religionists.
    — Palfrey.
    It might be that an Antinomian, a Quaker, or other heterodo religionists, was to be scourged out of the town.