One of the most popular "Christian" books ever is "The Shack". Many churches are using it for discussion groups during Lent. Evangelical Pastors I know think it is wonderful and highly recommend it. Reviewers are ecstatic in their praise. Many claim the book has radically changed their lives for the better. However, it is full of serious unscriptural teaching and should be read, if at all, with a prayer for spiritual discernment.
Many who wouldn't recognize the beliefs and values of the so-called Emergent Church will find them in the pages of this book. Solid believers will begin their reviews saying, "I know there are yellow flags and I have serious problems with the doctrine in the book", but go on to say, "nevertheless, I love the book and found it so freeing." That is the word used often. In the book, as in the Emergent Church literature, relationships trump doctrine. What is most important is love, acceptance, affirmation, forgiveness and reconciliation. They find all of that in this book and that is what really matters to those who love the book, even if it is unsound in its teaching about God, the Trinity, Salvation and the Scripture. (What does that say about people in general and contemporary evangelicals in particular?) Here is an excellent, extensive review of the book that should serve as a guide if you are spending time in the Shack.
http://www.challies.com/media/The_Shack.pdf