Knowledge is soon changed, then lost in the mist, an echo half-heard.
He's not rewarding us by talking to us. He's talking to us because He has something to say to us directly, as opposed to the things He says to all humanity.
You seem to think that the only genuine existence evil can have is conscious existence - that no one is evil unless he admits it to himself. I disagree.
Ambiguity is necessary in some of my stories, not in all. In those, it certainly contributes to the richness of the story. I doubt that thematic closure is never attainable.
My whole life experience feeds into my writing. I think that must be true for every writer. Clearly the Army and combat were major influences; just the same, you need to understand that many of the writers we have now couldn't load a revolver.