Good Book vs Holy Scripture

Good Book and Holy Scripture both are nouns.

Word	Noun	Adjective	Verb	Adverb
Good Book	Yes	No	No	No
Holy Scripture	Yes	No	No	No

As nouns, Good Book and Holy Scripture are synonyms defined as:

Good Book and Holy Scripture: the sacred writings of the Christian religions

Other synonyms of Good Book include Bible, Book, Christian Bible, Holy Writ, Scripture, Word, Word of God.

Good Book (noun)	Holy Scripture (noun)
the sacred writings of the Christian religions	the sacred writings of the Christian religions