I picked up The Shack a while back because I was about to get on a plane and I was afraid I'd run out of things to read. That and I'd read so much about the controversy surrounding the book: some people swearing it was the most encouraging, enlightening, spiritually nourishing and beneficial book they'd ever read, others saying it was just a gloss on old heresies, others claiming it was the tip of a nasty iceberg of creeping New Age-ism in the modern church. Etc.
I'm beginning to suspect after reading this book (along with Brian McLaren's A New Kind of Christian trilogy) that theology makes for lousy novels. One thing this book shares with McLaren's book is that most of the dialog in the essential parts of the book is wooden, with one character playing straight man for the other, adding leading questions, and the character(s) serving as mouthpiece for the author delivering lines that might as well start "I'm glad you asked that, Steve..." or whatever.
The story involves a man whose daughter was murdered and who becomes bitter afterward. God invites him to the shack where the girl's bloody dress was found, and he takes a weekend and goes to meet God. The central part of the book involves three days he spends at the shack, which along with its environs has been transformed by God's presence there. God appears in three literal persons: two women (one black and one Asian) and one man (Jesus, a Palestinian Jew). The middle half to two-thirds of the book take place at the shack. At the end of the weekend the man heads back to town, is in an automobile accident, and discovers that he was actually returning on the day he left (leaving the three days he spent away somewhat ambiguous); the one sign he has that he's really been away three days is that God shows him where his daughter's body was hidden, and toward the end of the book he's able to take the sheriff to the location of the body, and in a needlessly happy ending investigators are able to extract enough detail from the scene to track down her killer.
It's a pretty wooden story, but no worse than a lot of other popular novels. Most popular novels make up for poor characters and dialog by having lots of action; not so The Shack. The author instead fills in the gaps with some practical theology. The only trouble is that he puts the words in the mouth of God, which is something of an unworshipful thing for a Christian author to do.
It's not a great book; it's not necessarily a good book. I'm pretty ambivalent about it: most of the objections and criticisms I've read I've found to be frankly spurious: people are offended by the fact that Young portrays God in the body of a woman, and suggest that this is because he's offering up some form of Goddess worship, but neglect to mention that he has the character say explicitly that God's neither a man nor a woman, and ignore the fact that the story doesn't really have the signs of Goddess worship: no fertility rites, no harvests, no birth narratives, no sexual rituals, etc. Others are offended by the fact that Young portrays God as having a body, accuse Young of idolatry, and neglect to deal with the difference between literal graven images and literary images. Etc.
I consider myself a fairly conservative, fairly orthodox Christian, theologically speaking, and I only found one passage troublesome: one where Young has his Jesus character saying he has no desire to make Christians out of people. I'd rather he'd said this differently or not at all.
Regardless, I'd probably consider it the Bridges of Madison County of the modern theology set; I wish people who get this upset about this book or The Da Vinci Code or whatever would read some of the novels considered orthodox, such as Pilgrim's Progress, or in some circles the Left Behind series with the same critical eye.