proselyte

v. convert someone to another religion or opinion

n. religious convert; one who changes his personal opinions or beliefs

Proselyte, from the Koine Greek προσήλυτος/proselytos, is used in the Septuagint for "stranger", i.e. a newcomer to Israel; a sojourner in the land, and in the New Testament (Strong's G4339) for a convert to Judaism from Paganism. It is a translation of the Hebrew word גר/ger (Strong's H1616).
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Noun
1. a new convert; especially a gentile converted to Judaism
(hypernym) convert
(derivation) proselytize, proselytise

n. proselyte, religious convert; one who changes his personal opinions or beliefs

(v. t.)
To convert to some religion, opinion, or system; to bring over.
  

(n.)
A new convert especially a convert to some religion or religious sect, or to some particular opinion, system, or party; thus, a Gentile converted to Judaism, or a pagan converted to Christianity, is a proselyte.