I don't want this to come off the wrong way, as my intent is not to bash anyone's specific religious beliefs. I was actually a pretty big Ted Dekker fan when I was younger, but my own religious beliefs have since changed and this is the first Dekker book I've had a go at since then. And, to be blunt: I found it disappointing as a story. Almost to the point of being insulted.
The premise is somewhat interesting, even if the back is extremely misleading: the main character spends a chapter trapped in a "coffin", not the entirety of the book. The rest is the two main characters "trapped" in a mental hospital.
To Dekker's credit, I liked some of the intense existential stuff that he played out in the situation, such as the question of "would you rather be right, or at peace?" And I still like the man's writing style; he is good at writing thrillers. For the most part.
Where it starts to fall apart are the characters. Dekker -both in this and other books- tends to write very one-dimensional characters: this guy is very smart, this girl is insecure. Everything they think, do, and say is based off that one quirk. It's not a fatal flaw, but it certainly doesn't help one get invested in the story. The second problem is what I'd just call "lazy writing". Something will happen that seems to come out of nowhere, and you accept it thinking that eventually it will all tie together; weird things happen which makes it seem like a thrilling, creepy story is going on that will slowly be explained to you, but it never is. They're just weird things that happen out of the blue.
What absolutely killed and buried this book is the ending. Because it has no end. I refuse to say that it does. He takes what is a fairly compelling thriller about a mental hospital and then just stops, and proceeds to spout what is almost Christian propaganda. Things stop happening to the characters and the characters cease to be characters. They are mere vessels through which the obvious Jesus character can spout a monologue that is so thinly related to the story that I began to wonder if it was actually intended as fiction.
All of that may sound harsh, but here's the bottom line: it absolutely destroys whatever the story had going. Objectively. It's not "I don't like the words he's (Dekker via the Jesus character) saying" it's a "this is the laziest and most boring ending imaginable". The fact that it's not just poor writing but that Dekker is quite obviously trying to write it off as "but it's got a good message" is enough to make me gag.
I'm sorry, but I'm not going to excuse a book for being crap even if it's a "Christian" novel. If you're going to write fiction, write good fiction. Don't even start this mess; it starts out promising, but it spends the entire time building to a climax that never happens and then just stops when the author decides that you're invested enough that you'll read whatever message he wants to say just to finish the book.