tenet vs credendum

tenet and credendum both are nouns.

Word	Noun	Adjective	Verb	Adverb
tenet	Yes	No	No	No
credendum	Yes	No	No	No

As nouns, credendum is a hyponym of tenet; that is, credendum is a word with a more specific, narrower meaning than tenet:

tenet: a religious doctrine that is proclaimed as true without proof
credendum: (Christianity) any of the sections into which a creed or other statement of doctrine is divided

Other hyponyms of tenet include article of faith.

tenet (noun)	credendum (noun)
a religious doctrine that is proclaimed as true without proof	(Christianity) any of the sections into which a creed or other statement of doctrine is divided