The story of good and evil is a timeless tale that has been told since the dawn of man. Always pitting the extremely good Samaritan against that ultimate and despicable villain. In the end after a long struggle the good always wins out.
But these tales which dominate our movies, sometimes our books and most certainly some religious texts don't really have any basis in reality.
I mean look at it for real. When have you ever met someone who was truly evil? Probably never? Ever met anyone who was pure good? I doubt it. While its all nice and convenient to sugar coat everything in to simple black and white, the reality is a big giant grey.
There are no really evil acts that people do. It's all simply actions that are justifiable for the person undertaking them and generally selfish in nature. It's all well and good to be a peace loving hippie when there is no conflict of interest whatsoever, but its when the small personal gains (and sometimes not so small) come in to the picture that everything tends to fall apart.