evangelist

noun

1. An itinerant or special preacher, especially a revivalist, who conducts services in different cities or locations, now often televised.
2. A writer of a gospel, especially the four New Testament Gospels (Matthew, Mark, Luke, and John), usually capitalized (Evangelist).
3. A person who first brought the gospel to a city or region.
4. A patriarch.
5. (broadly)A person marked by extreme enthusiasm for or support of any cause, particularly with regard to religion.

   “Booth, William (1829-1912) English evangelist; founder and first general of the Salvation Army ... his subordinates being expected to give him unquestioning obedience.”

   “Yet in the spreading consumer market of the mid-1700s, his renditions competed with others offering a far different account of the evangelist and his message. The famous artist William Hogarth mocked Whitefield in two engravings presenting the revivalist as a religious fanatic who held sway over the superstitious lower orders.”

   “The film implies that the evangelist, as a type, is a fanatic, a sanctimonious prig, and ultimately a hypocrite.”

   “Hendy has come out as something of an evangelist for discontinuous electrification. For Waterloo-Exeter, this could make real sense on a route where the high capital cost of wiring or third rail all the way to Devon would be prohibitive. But what about his vocal support for it on East West Rail, which is effectively a brand new line?”

6. A person hired to promote a particular technology.

   “developer evangelist”

   “[…] and has worked in multiple roles, including as the C# Product Manager and as a Developer Evangelist in the Mid-Atlantic district.”

7. A writer of a gospel, especially the four New Testament Gospels (Matthew, Mark, Luke, and John), (also evangelist.)