First, it most be pointed out that in order to ask this question one must assume that the Bible is not what it claims to be namely the very Words of God. Thus ones perspective on this matter will not change because of this underling assumption. However, why doesn’t everyone assume the Bible is what it claims to be the very Words of God? It is because most people have a prejudice towards the Bible. And have assumed the Sovereign God of the Bible does not exist, and that miracles like the preservation of the Biblical text are impossible. These unargued biases towards the Bible need to be argued and defended before the question concerning the Bible’s authorship can be answered. If not, the one asking if the Bible is the Word of God is inconsistent because he or she seeks justification for the belief the Bible is the Word of God, but will not justify their unargued (bias based) beliefs. The Christian perspective is the Bible is the Word of God. Unlike non-Christians, Christians do not have a prejudice or unargued bias towards the Bible. They acknowledge what the Bible claims to be the very Word of God. And Christians understand that if God speaks to us by a book we would have to believe it on God’s testimony. For example, if a human being was testifying on their own behalf in court he or she did not commit murder the judge would question their testimony, but if God testified on His own behalf we could not question His testimony because of who He is the ultimate authority.
To answer this question directly the Bible is the objective foundation for rationality and knowledge. If the Bible is not true then we have no basis for proving or knowing anything. I will expound on this soon.
Unless the Bible be true we cannot prove anything.