Though we speak of the Bible as one bok (and it can rightly be considered as such), it is also a collection of documents written by about 40 different divinely-inspired authors over a period of at least 1,500 years. Each document was originally written as a stand-alone letter, historical account, prophetic message, group of worship songs, or a collection of wise sayings.
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Note: The writings of the Old Testament are arranged by type of writing. They are not in strict chronological order although there is then quite a bit of chronological order within each grouping. [ Another Another way of understanding how the biblical writings are organized ]
-- Howard Culbertson
Questions answered by the Old Testament Cliff's Notes version: The Bible in 50 words 15 key Bible chapters How to study the Bible