What? How is he right in any way? I never said that what is not in the Bible is automatically not true? That is blatant lie!
I simply said that Cain had a sister for his wife or a relative; however, theoretically, God could have made her from dust, like Adam.
I don't believe it to be the latter; however, that is irrelevant, since it still could have happened. There was no need to put it in the Bible, so its to conjecture. I don't care which one it is.
The point, though, is that I never said that the things that are not in the Bible are not true; that is a lie and he knows it, since he loves to deceive. You know that from discussing the ending of John with me, in which I said that there were many things that Jesus did that could not be put into the Bible, since it would be too much to write down.