One of the many internal proofs of the Bible is the fact that in spite of being written over a period of 1500+ years by 40 different writers, there is a united, consistent flow of themes and ideas. Histories presented in the Old Testament are fleshed out and given added meaning in the New Testament. The promises of God are shown to come to pass. Some prophecies have details added as the Bible progresses through time. We can be assured that the Bible is indeed the complete, inspired Word of God by the unity of the Scripture.