THE BIBLE
The Bible is a divine library of 66 books, written over 1,500 years, by about 40 writers of different periods, and backgrounds. The two grand divisions in the Bible are the Old and New Testaments. There are 39 books in the Old Testament and 27 books in the New Testament. The division in the Old Testament was mentioned by Jesus in Luke 24: 44.
And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me.
(Luke 24:44 KJV)
DIVISIONS IN THE OLD TESTAMENT
1. Law
2. Prophets
3. Psalms (Poetical Books)
ARBITRARY DIVISIONS IN THE NEW TESTAMENT
1. History (Gospels + Acts)
2. Doctrine (Epistles)
3. Prophecy (Revelation)
Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.
(2 Timothy 2:15 KJV)