Scripture vs religious writing

Scripture and religious writing both are nouns.

Word	Noun	Adjective	Verb	Adverb
Scripture	Yes	No	No	No
religious writing	Yes	No	No	No

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

Other hypernyms of Scripture include religious text, sacred text, sacred writing.

Scripture (noun)	religious writing (noun)
the sacred writings of the Christian religions	writing that is venerated for the worship of a deity