Book - The Screwtape Letters by C.S. Lewis

I just got done reading "The Screwtape Letters" by C.S. Lewis.  I'm not sure what to think of this book.  It kept bothering me and I can see why it would have been hard to write.  I thought it was well written.  It was strange to see a glimpse of how the other side operates.  It made a lot of sense, just bothered me to read it.