I'm not sure how your friend read all of those fallacies into your response. What it does sound like, though, is that your friend already has a faith commitment in that he will not allow God to be His own ultimate authority. It sounds like he is saying that you cannot use the Bible to prove the Bible (circular reasoning).

However, an ultimate authority is, by definition, self-attesting. If you can prove anything by something else, then that is not an ultimate authority. If God is God, and He is ultimate (by the very nature of being God), then what else other than a word from God could attest to the veracity of the Word of God? If there were any other standard (outside of the Word of God) by which we could examine and prove the truthfulness of God's Word, then God would not be ultimate.

__________________
~~Greg Carpenter~~
Deerfield Beach, FL

"It is a throne of grace that God in Christ is represented to us upon; but yet it is a throne still whereon majesty and glory do reside, and God is always to be considered by us as on a throne." –John Owen