Good and evil are figments of man's imagination, our artistic representations of what sooths us and what we fear. Is it any wonder that things that are supposedly evil are always mysterious like the darkness, menecing like a snake or lion's face, red like blood, which otherwise rarely occurs in nature, and supernatural in a way that robs us of our sense of ability to protect ourselves? Evil doesn't really exist.

Horror movies work by making us sympathize with the main characters before they subject those characters to various frightening scenarios. Those scenarios always tease at our needs for physiological safety, security and love/belonging. The security and physiological parts are obvious. The love/belonging part has to do with the slasher sometimes being somebody that's trusted or that the killer is psychotic so they can't be reasoned with.

Below is an image of Maslow's Heirarchy of Needs. You can see how this fits in with movies. Action movies and whatnot usually have to do with self-actualization and esteem. Horror movies work on the physiological, security and love/belonging levels.

The so-called evil found in the Bible is imaginary. There's no enemy out there trying to manipulate you and keep you from the promise. If there were, how could you be held responsible for being manipulated by a monster you normally don't know is there? Evil is humanity's artistic representation of what we are afraid of. The things we are really afraid can be easily explained with psychology and the theory of evolution.