prayer vs religious person

prayer and religious person both are nouns.

Word	Noun	Adjective	Verb	Adverb
prayer	Yes	No	No	No
religious person	Yes	No	No	No

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

prayer (noun)	religious person (noun)
the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)	a person who manifests devotion to a deity
earnest or urgent request
a fixed text used in praying
reverent petition to a deity
someone who prays to God