I believe that the Bible states its case that it doesn't need to be proven by human means. Christianity is based on the Bible. The Bible eludes to the idea of faith. If you can prove something...you don't need to have faith in it. So, the Bible doesn't need to be "proven" as much as it requires one to have faith. Also, I believe that God has worked throughout history to keep His Word pure and faultless or else He wouldn't call it pure and faultless. Yes, things are added and taken away in different translations, but I believe that God can use anything to bring others to Him. Also, the Bible is the book that we have the most, accurate manuscripts (based on close relation to authors) than we have of any other ancient book.