This is a well written fictional novel that crosses several genres: fantasy, horror, action/adventure. The story is fast paced, wrapping you up from the beginning and the characters are engaging. You may find yourself sympathizing with both protagonists and antagonists in the story, and they tend to overlap, much like in real life. The main character's struggles with addiction ring true, along with the accompanying personality traits. There are elements of religion in the book since it is centered on the struggles of a fallen angel, but they are elements of the fictional story and I wouldn't recommend this as a bible study text. Enjoy!