Yes, the Bible is the Word of God. But no one can PROVE the Bible is the Word of God. It's a theological perspective, not a provable events.
But here's why I believe it is. Hundreds, if not thousands, of times, the writers say, "And the Lord said." The Bible is God's revelation of Himself, and therefore His word. The Bible is God's interaction with humanity and His involvement in history, and therefore His word. The Bible is God's instructions to us about how to fulfill our creation mandate which is how to be in relationship with Him, and therefore it is God's word.
In addition, we can assess the value of the words by examining their merit as (1) historical record, (2) accurately describing humanity, (3) evidencing wisdom, and (3) conforming to truth. Anyone can read the Scripture and tell it is not the distorted words of posers.
In addition, the absolute brilliance of the literature of the Bible, along with the unity and consistency the Bible displays in theme and teaching, combined with the prophecy and fulfillment shows that the Bible is above purely human capability.
Now let's get into it a bit. Third, but I believe there are plenty of evidences that lead me to plausibly accept the Bible as the Word of God.Any lawyer will tell you there are different kinds of evidence: material evidence, circumstantial evidence, testimonial evidence, anecdotal, statistical, reasoning, documentary, historic, scientific, etc. Different kinds of evidence are valid in different situations. For instance, a lawyer may use scientists, eye-witnesses, circumstantial evidence, and testimonial evidence to bring his case to a jury, who must weigh the various evidences to arrive at a verdict. If science were the only evidence, court cases would be decided by scientists, not juries. But a whole lot more is involved. Evaluating the Bible is more like a court case than a science experiment. We have to use the proper measures in appropriate places. Miracles can't be proven by science because they're not repeatable on demand, or even able to be studied by reproducibility in controlled environments (the only appropriate arena for scientific inquiry).
Here are some of the reasons I believe in the Bible:
1. Corroboration with history (history is always a matter of interpretation of records). The Bible has shown itself to be true in the relating of historical events.
2. Corroboration with archaeological finds (becoming more scientific all the time, but still subject to a vast amount of interpretation)
3. Corroboration with known cultural (in history) markers.
4. Corroboration with known geographical information.
5. Reliable anecdotal evidence from trustworthy sources.
6. Reason: The Bible gives a well-reasoned and consistent perspective and interpretation of life as we know it. The picture it presents makes sense.
7. Testimonial evidence (of people currently alive), consistent from person to person, of life change founded in a religious experience as described in the Bible. People's lives are still being radically changed by what they say is the truth of the Bible and the Holy Spirit inside of them.
8. Current realities (like the existence of the state of Israel and the existence of the Church) that don't make as much sense outside of the environments and interpretations described by the Bible.
9. The eyewitness accounts of the Bible ring true.
10. There is no hint of any kind of conspiracy, fraud, or collusion.
11. The writers of the Bible exude nobility, morality, and honor. To accuse them of deliberate deception is unreasonable. There is no hint that these men were insane. While they certainly lived in a non-literate culture, they didn't live in an illiterate one. These people were obviously not buffoons, barbarians, or blockheads, but were demonstrably fairly cogent and logical.
12. The consistency of theme, theology, and focus from over 40 authors from 3 continents over a span of 1600 years is unearthly.
13. Prophecy and fulfillment
14. The events they wrote about were public occurrences, not private experiences. Detecting fraud or error would have been easy.
15. Their writings have been pored over for millennia and have been accepted by great numbers of scholars.
16. The Bible has an unearthly kind of power to change lives for the people who submit to its teachings.
Well, that's 16 off the top of my head, at least enough to stimulate dialogue.