gospeller(n = noun.person) evangelist, gospeler, revivalist - a preacher of the Christian gospel;
is a kind of preacher, preacher man, sermoniser, sermonizer
has particulars: televangelist, billy graham, graham, william franklin graham, aimee semple mcpherson, mcpherson, dwight lyman moody, moody, oral roberts, roberts, billy sunday, sunday, william ashley sunday

gospeller, n. the reader of the Gospel in a Communion service.

Idiom:
hot gospeller a zealous puritan; a rabid propagandist.