Book vs Christian Bible

Book and Christian Bible both are nouns.

Word	Noun	Adjective	Verb	Adverb
Book	Yes	No	No	No
Christian Bible	Yes	No	No	No

As nouns, Book and Christian Bible are synonyms defined as:

Book and Christian Bible: the sacred writings of the Christian religions

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

Book (noun)	Christian Bible (noun)
the sacred writings of the Christian religions	the sacred writings of the Christian religions
the sacred writings of Islam revealed by God to the prophet Muhammad during his life at Mecca and Medina