The doctrine of Scripture's self-authentication is a jewel rarely discussed. The implications run far and wide. If you haven't yet considered this truth, or if you would like to hear a clear presentation, check out Michael Kruger's lecture. It is worth every minute.
Tim McGrew and Bart Ehrman recently debated issues surrounding the Gospels. In their first exchange, I think Ehrman got the better of McGrew, unfortunately. This is due in part to some weaknesses in McGrew's theological substructure. Nevertheless, in the second debate, which I am recommending, McGrew exposes a number of Ehrman's presuppositions while discussing the subject of undesigned coincidences. I found it to be a fascinating discussion. You can find it here.