The Shack is a book, by Wm Paul Young, loved by some and hated by others. It has a focus on God that cuts across the grain of typical traditional views. Consequently, those who feel the need to justify the past and avoid the future will probably dislike it. But for those who feel that Christianity is about where we seem to be headed rather than where we seem to have been or how we think we got to where we are now -- you are going to love it.
A word of warning: if you hate books that on one page say things you think are awesome but on another page say something that contradicts what you thought you were sure about, well then stay away from this book. It will make the pebbles inside your shell a bit more uncomfortable. On the other hand, if your heart longs for a faith that seeks intimacy and relationship as more important than sustaining tradition, then you will enjoy the entire book.