Proof? Here are just a few verses: 2 Timothy 3:16 All scripture is inspired by God and is useful to teach us what is true and to make us realize what is wrong in our lives. It corrects us when we are wrong and teaches us to do what is right. 2 Peter 1:20-21 Above all you must understand that no prophecy of Scripture came about by the prophets own understanding or from human inititive. No, those prophets were moved by the Holy Spirit, and they spoke from God. 1 Thessalonians 2:13 And we so too constantly thank God that you recieved God's message that you heard from us, you accepted it not as a human message,but as it truly is,God's message,which is at work among you who believe. There are other verses also,if you want to see them....do a search. As far as "proof" all I can say is that the Bible has done every single thing it has said it would do in my life as long I did what it told me to do. To have "proof" does away with faith,people are saved by faith. God through Jesus has done things in my life and changed me in ways I could never do on my own. If you knew me or what I had been involved in you might agree. Here is just one page....
www.bible.org/seriespage/bible-written-word-god