Forgive me if this has been stated already. I've been pissed off about this for some time and wanted to get it out of my system. Thanks for letting me rant, and let me know what you think! 

Good and Evil: The Ultimate Black and White Fallacy?

Every argument I have with my Christian friend ends up with him basically saying, "Where do you have your basis for morality? How can you decide what is right and wrong? What is good and what is evil?
I'm not really that old in cosmic terms, just 25. But even in my short time here on this planet, I've never really thought in terms of "good" and "evil". Why is it that religious people tend to think that for every situation, one can logically come to a conclusion that one specific event is either good or bad? Furthermore, they often think that any other person must come to the same conclusion that they would.
This never happens in real life, or very, very rarely. We can take an example of a mass murderer. He gets sentenced to death and is killed. Many people would agree that that was a good thing. Do you think his mother thought it was a good thing? Many people, I think, disagree with capital punishment, so that's not even a good example, I suppose.
So let's try a different example. Let's take it with respect to Christianity too, cause I know that best. If a young child in an Indonesian whorehouse ends up going insane and killing the person raping them, was that wrong? Was that young child at fault? Is God going to say, "I TOLD YOU NOT TO KILL ANYONE!" This, to me, is utterly stupid.
When I bring an idea like this to my Christian friend, he tends to resort to the, "You can't always know the end outcome. It may have had a positive outcome." I would argue, then, that he indeed has no basis for his morality, as he says he does. If he cannot conclusively say one way or the other that a tidal wave killing a quarter of a million people is good or bad, then I don't believe he is a moral person. He may not be immoral, but he is at least certainly amoral.
From my perspective, it seems like all apologists (to my knowledge anyway) are not realizing that their "good book" (if the religion has one) uses a black and white fallacy in its statement of morality. Furthermore, when they say they have a standard for their morals, what they're really saying is they're full of bullshit. "That tidal wave may have had a positive outcome." Bullshit my friends, bullshit.
So, in one way they're using a black and white fallacy saying everything comes down to either good or evil. Then they're admitting that they can't really know that the outcome of specific events are good or evil. This, to me, says that they truly don't have a basis for their morality. Not even that they're necessarily "afraid" of going to hell. They literally do not have a basis for it.