From The Art and Popular Culture Encyclopedia
Proselytism is the act of attempting to convert people to another religion or opinion. The word proselytize is derived from the Greek language prefix προσ- (pros-, toward) and the verb ἔρχομαι (érchomai, to come) in the form of προσήλυτος (prosélytos, a new comer). Historically in the Koine Greek Septuagint and New Testament, the word proselyte denoted a gentile who was considering conversion to Judaism. Though the word proselytism originally referred to Early Christianity (and earlier Gentiles such as God-fearers), it now refers to the attempt of any religion or religious individuals to convert people to their beliefs, or any attempt to convert people to a different point of view, religious or not. Proselytism is illegal in some countries.