I saw The Shack last night after my brother and his wife gave it a rave verbal review. The story is an exploration of the mystery of why bad things happen to innocent people. Not too surprisingly, the audience was middle-aged, with significantly more women than men. I saw no teenagers. At certain points, the silence in the theater audience was as dramatic as the scene on the screen. Throughout, I heard sniffles from the woman to my left, and afterward, I overheard the woman to my right saying the movie was "Awesome." I confess that my (outwardly) stoic self came to tears several times as well. My experience of previously reading the book had been that of an awful literary style detracting from an excellent narrative. This is an uncommon case where the movie is better than the book. The problem with most movie adaptations of books is that the medium and time limit require the filmmaker to leave out much of the substantiating richness of the characters, plot, mood, and so on, from the source material. Movies also tend to downgrade stories by minimizing the role of the imagination. But The Shack gave the movie makers the opportunity to focus on the essential elements only while replacing the lousy literary style with professional cinematic storytelling. The only nitpicking negative criticism I'd make is that the Holy Spirit girl (played by a Japanese actress/model) was a bit too ethereally cold for me. I would have preferred a more sexy, or at least earthy, spiritual appeal. Theological and philosophical interpretations and meaning are above my educational grade, so I'll leave it to you to do the work of interpreting your own experience of the film.
The Rogers Ebert website gave the film only one and a half stars, calling the spiritual content pabulum. I will agree halfway--much of the spiritual content is presented as if for childish minds. But not to the point where it insulted my intelligence. However, the film's question, and exploration of an answer, of why do evil things happen to good and innocent people stands on its own.