"The teachings were initially verbal and written by man."
This is true but if you were to read the Bible quietly, unrushed, with an open heart, you should be able to HEAR the truth and the Holy Spirit in those words. (It might also help to PRAY beforehand that the Lord would soften your heart.)
These people who wrote the Bible had first-hand experience with what happened. They saw and experienced it all. God put these people in a position to not only witness the event, but worked through them to spread the Gospel itself. I believe the Bible is absolutely Divinely inspired, despite being written by imperfect men.
And sealion is correct...it is either all truth or all lies. There is no in between. You either believe it all, or you don't. The Bible draws a line in the sand for everyone.