Christians believe that the Bible is the word of God! But not necessarily every person on this planet has the same beliefs about the Bible as we do. Among the seven billion people in the world today, nearly one hundred and fifty million do not even believe that there is a God who created everything in the universe and he will judge the world in the end.
People are left to believe in the existence of God but differ greatly on who he was. There are more than two billion people profess to be Christians, and they consider the word of God of the Bible. However, not all of them regard it as equally authentic, authoritative, and binding on all. You can get more information about ac and bc timeline online at https://amazingbibletimeline.com/blog/before-bc-and-ad/.
The Bible is a summary of both the Jewish Scriptures, which is a collection of 39 individual books called the Old Testament (O.T.), and the Christian Bible, which is a collection of 27 individual books called the New Testament (N.T.).
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In addition, Roman Catholics added seven other Jewish history books called apocryphal books with Hebrew Scriptures while the Greek Orthodox adding twelve of them. As far as the Christian Scriptures were concerned Protestant, Catholic, and Orthodox Christians all agreed about 27 books.
Even with regard to the Jewish scriptures, the Tanakh (O.T.), all these groups agree on 39 books. However, they differ only in the apocryphal books added to the Jewish-Protestant Bible is not added, adding seven Catholics and Orthodox adding twelve. So the disagreement among these groups about the size of the Bible is peripheral.