That said, I do believe "The Shack" purports to answer questions it never actually does and probably cannot be answered, one of which being: Why does God let bad things happen to his people? The conversations between God and the main character, Mitch, tip-toe around this conundrum and the plot (what little of it there is) progresses as if the question gets answered, but it doesn't. As a reader, I find this to be incomplete and frustrating -- if it cannot be answered, why base an entire novel on the question?
I also draw issue with the personification of God's wisdom as a smokin' hot woman named Sophia (which, surely not so incidentally, means "wisdom"). When Mitch asks Papa if she is a fourth person of what he believed to be a trinity, God assures him that she's not. I took this to be some of the theology a lot of Evangelicals called into question when the book was first released. Though I completely understand "The Shack" is a work of fiction, I feel that great care must be taken when fictionalizing the ultimate reality, and too many liberties should probably not be taken outside of what God reveals to us directly through the Bible.
I know a lot of people who hold this book very dear and others who completely hate it. I am neither. I understood the subject matter, but honestly found it to be boring at times. I generally finish a book of this size (248 pages) in a day or two, but it took me almost two weeks to finish because I didn't want to read more than a few pages a day.
I think this book might be best for a Christian who needs reassurance that God is loving or for Christians who are hurting. I wouldn't dissuade non-Christians to read it because much of the message is positive and biblical. I would, however, remind those readers that not everything in the book can be backed up by the Word. Be ready to answer questions with Scripture that those readers might have about the book's content or otherwise.