http://www.bibleinfo.com/en/questions/who-wrote-the-bible

40 authors wrote the Bible over a period of 1,500 years. These Bible writers wrote as they were inspired by the Holy Spirit (see 2 Timothy 3:16-17). [1] Moses was the first person to write portions of Scripture while John, the disciple of Jesus, was the last. Other famous people who wrote the Bible include: David, Daniel, Peter, Paul, Jonah, Isaiah, Solomon and David.

Those who wrote the Bible lived at different times, some separated by hundreds of years. In many cases they were complete strangers to one another. Some Bible writers were businessmen or traders; others were shepherds, fishermen, soldiers, physicians, preachers, kings—human beings from all walks of life. They served under different governments and lived within contrasting cultures and systems of philosophy.

But here is the wonder of it all: When the 66 books of the Bible with their 1,189 chapters made up of 31,173 verses are brought together (KJV), we find perfect harmony in the message they convey. As the great scholar F. F. Bruce noted: "The Bible is not simply an anthology; there is a unity which binds the whole together."

The Bible writers gave God's messages by voice and pen while they lived, and when they died, their writings lived after them. These prophetic messages were then gathered together, under God's leading, in the book we call the Bible.