revivalist

One who promotes or leads religious revivals.

One who revives practices or ideas of an earlier time.

One who is instrumental in producing or promoting in a community a revival of religious interest and activity: specifically applied to an itinerant preacher who makes this his special work.

In general, one who revives anything, as an old custom, trade, or word.

A clergyman or layman who promotes revivals of religion; an advocate for religious revivals; sometimes, specifically, a clergyman, without a particular charge, who goes about to promote revivals. Also used adjectively.