religious outcast vs pariah

religious outcast and pariah both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious outcast	Yes	No	No	No
pariah	Yes	No	No	No

As nouns, pariah is a hypernym of religious outcast; that is, pariah is a word with a broader meaning than religious outcast:

religious outcast: a person who holds religious beliefs in conflict with the dogma of the Roman Catholic Church
pariah: a person who is rejected (from society or home)

Other hypernyms of religious outcast include castaway, Ishmael, outcast.

religious outcast (noun)	pariah (noun)
a person who holds religious beliefs in conflict with the dogma of the Roman Catholic Church	a person who is rejected (from society or home)