A missionary is a member of a church, follower of a single diety or a pantheon who takes their belief to the unbelievers of other lands. Similar in many ways to a heretic but in place of concealment and plotting a missionary is open and honest in their preaching.
Missionaries that dare to venture to hostile lands rarely return, but those that take less risky routes can spend many, many, years away. Return of a missionary is often rewarded by a place in the church for such devoted followers, and one of rest, relaxation and contemplation.