“That is the problem. I am coming from a completely different metaphysics and epistemology than a Christian would have to hold to hold the beliefs he or she holds.”
It doesn’t take metaphysical, epistemological, blahblahizicalmological anything to understand your own nature. Even Nietzsche understood the blackness of despair, and his own inability to live up to his own philosophy. His philosophy was aimed not at those who were there now existing, but of a Overcomer who would come later, in another time. Ironically, the only people who will be able to live up to those standards is the Christian in his Resurrection body.
If you say that you yourself are not corrupt, then give me your code of moral conduct. Give me its dictates, what defines good behavior. How do you handle lust? How do you handle lies? How do you handle any of the problems you yourself face or think you face. And then tell me, after all of that, if you even keep your own standards. Or if, like a blind man, you are always grasping for them and failing to truly live up to them at all times.