Good versus evil. Does it truly exist? What are the gray areas? Do good people do bad things?

Good and evil truly does exist. It's true that some people do bad things for the sake of their family, but some people are just plain evil and cruel. Kim Jung Il, the leader of North Korea, what good is he doing? For his people? nothing. He sucks up the treasures and every little thing they have for his glory and pleasure. He is an example of pure evil. He does nothing for the sake of his people, but rather everything for the sake of his own  pleasure. Period. End of Story.