religious sect vs religion

religious sect and religion both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious sect	Yes	No	No	No
religion	Yes	No	No	No

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

Other hypernyms of religious sect include faith, organized religion.

religious sect (noun)	religion (noun)
a subdivision of a larger religious group	a strong belief in a supernatural power or powers that control human destiny
	an institution to express belief in a divine power