Christian church vs religion

Christian church and religion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Christian church	Yes	No	No	No
religion	Yes	No	No	No

As nouns, religion is a hypernym of Christian church; that is, religion is a word with a broader meaning than Christian church:

Christian church: one of the groups of Christians who have their own beliefs and forms of worship
religion: an institution to express belief in a divine power

Other hypernyms of Christian church include faith, organized religion.

Christian church (noun)	religion (noun)
one of the groups of Christians who have their own beliefs and forms of worship	a strong belief in a supernatural power or powers that control human destiny
	an institution to express belief in a divine power