|Preach to the choir|
|Crux of the matter|
|Speak of the devil|
|An act of faith|
Evangelism (from the Greek ευαγγελος, "evangelos", "good message") involves the act of proselytizing a position — usually, but not always, a religion — on the basis of some "truth value". The term is also used for the promotion of various philosophies in politics and in technical fields, particularly in computing, and has become marketing jargon. The concept springs from the spreading of the Christian gospel (ευαγγελιον, "evangelion" — literally from roots meaning "good news").
Not all religions actively engage in proselytization; while most Christian and Islamic denominations, for example, by-and-large insist on trying to bring in new members (sometimes even with the threat of violence), Judaism often actually discourages conversions and Shinto — which is based more around geography than around dogma — generally lacks the concept of "conversion" altogether.
- In particular, Scientology refers to this technique as "gradient", while the Mormon Church uses the somewhat less technical phrase "milk before meat". Both concepts implicitly recognize the difficulties that outsiders often have with accepting weird doctrines.
- Taking out of context, for example, Matthew 28:19-20 — "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you [...]."