I figure the anger in me is the one I am most able to do something about. Learning how to properly deal with that anger I expect is a good thing to do lest it fester and grow until the anger in me turns into the evil in me. Which I suppose from your viewpoint would be evil out there in the world... so yeah, there can be/is evil the the world. Only I expect it is evil in the hearts of men. As far as devils and demons go, those I am not familiar with. Although as I recall from childhood there was a guy we called the booger man, we all avoided him like he was a demon, but I doubt he was actually evil, just a bit gross.