Certainly good and evil exist, but is that really all there is? If there is only good and evil, how do you explain the story of Joseph in Genesis? His jealous brothers sold him into slavery and told their father that a wild animal had killed him. Much later when they were reunited, Joseph told them that what they had done was meant to be evil but God had used it for good. Because of their evil act, his family was saved from famine and the Jews developed into a mighty nation. I believe that God uses people to accomplish his will in many ways beyond our limited understanding.
Moral of the story "evil has its uses." I don't disagree with that