Well, you look at the prophecies given in the Old Testament and then you see them being fulfilled in the New Testament:
http://mb-soft.com/believe/txh/proph.htm
The dead sea scrolls, which were found in the 1940's date back to the time BEFORE Christ, and they contain prophecies about Christ which were fulfilled. This is obviously the work of God. And you can also take heed to the prophecies Christ made. For example, He predicted the fall of the temple in Jerusalem (Matthew 24:2, Mark 13:2, Luke 21:6) and it happened in 70 A.D. And you also have to take into account that the Bible was written by many men of God in different eras, and yet their writings go together. Also, with all the bashing the Holy Bible has taken from skeptics, it still remains after all these years, and it is the #1 selling book in history. God continues to leave people without excuse.