As I see it, like posts above, Good and Evil are purely subjective. but here's my take on it.
At a personal level the definition of Evil is something that goes against your nature, and you following through even though you hvae any of the following (the degree that you disagree determines how "grey" the issue is):
1. You have guilt associated with it
2. You have remorse because it goes against your character
3. You understand that in your terms it would be an "injustice" however slight .
while these are very vague, I think that Good and Evil are driven by these precepts. Serial killers sometimes feel that what they have done is justified, and have no remorse or guilt. In thier eyes they have done no wrong, while in yours its completely the opposite.
I guess tying this in for any Religeon just complicates the issue as in any organiation like that there is pressure to identify and address these "evils" which can drive people to do outstanding things int he name of "good".
I feel that Karma is a very real thing, and I try to ensure that I only have beneficial things coming my way ..
that's my $.02
