religious belief vs belief

religious belief and belief both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious belief	Yes	No	No	No
belief	Yes	No	No	No

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

religious belief: a strong belief in a supernatural power or powers that control human destiny
belief: any cognitive content held as true

Other hypernyms of religious belief include supernatural virtue, theological virtue.

religious belief (noun)	belief (noun)
a strong belief in a supernatural power or powers that control human destiny	any cognitive content held as true
	a vague idea in which some confidence is placed