Here is a funny story about atheistic propagandists.
Addendum: Here is the definition of "propagandist" from the Oxford English Dictionary, 2d ed.:
propagandist, n. (a.)
A. n.
1. A member or agent of a propaganda; one who devotes himself to the propagation of some creed or doctrine; a proselytizer.
2. spec. A missionary or convert of the Roman Catholic Congregation of the Propaganda.
B. adj. Given or inclined to propagandism; devoted to the propagation of doctrines or principles.
Hence propagan'distic a., of or pertaining to propagandists or propagandism; propagan'distically adv., in a propagandist manner.