Let me mention the most important evidences:

The Bible says in Timothy 3:15-17, “. . .from childhood you have known the Holy Scriptures, which are able to make you wise for salvation through faith which is in Christ Jesus. All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work.”

So first of all the Bible does not claim to be the very pen of God, but written by men inspired by God. The Holy Scripture is 66 individual books, written on 3 continents, in 3 different languages, over a period of approximately 1500 years, by more that 40 authors (who came from many walks of life), the Bible remains one unified book from beginning to end without contradiction.

Another indicative evidence that the Bible is the word of God is all the thousands of detailed prophecies where all, except those who deals with the end time, have been fulfilled with 100 percent accuracy.

Another thing is it details historical events that are subject to verification. All the historical and manuscript evidence supported by archeology makes it the best documented book from the ancient world.