Doug Beaumont has written a very interesting case for the validity of Christianity which you can find here.
His conclusion is that we can build a strong case for Christianity without the need to defend the Bible. He calls it the “zero facts approach” and essentially says that we have a strong case without defending the Bible in the least. One of Beaumont’s main points is that the church succeeded in its mission prior to the formation of the Bible, and today still succeeds in lands where there is no Bible. He holds that the existence of the many external evidences are sufficient to show the validity of central Christian doctrine.