By authority, I don’t mean his personal or academic credentials. I mean his authority to claim he can rightly interpret the Bible. Unless I am addressing a Mormon in which case his authority is the Book of Mormon, he claims to fall back himself as authority. Scripture says this or Scripture proves that, because he says so.
He can't prove from the Bible that the Bible is the only rule of faith. He can't tell me how he knows which books belong in the Bible in the first place. And his assertion that he has the authority to interpret the Bible for me on saints or any other matter is ridiculous, in light that there is nothing that would be sufficuent in deeming his interpretations will always be accurate.
Until he can come up with a better answer then I am done arguing with him.