I've seen some reviews which claim that all religious related subtext was subdued or removed from the movie. Did this result in a movie which is significantly different from the book?
Apart from the obvious (leaving out the ending because it would fit better in the sequel), the film largely followed the plot of the book. Of course, some scenes from the book weren't in the film. But the plot of the film was very much like the plot of the book (to a similar level of the first couple of Harry Potter films).
The main difference of the film from the book was the fact that a lot was explicitly in the film in dialogue and voice-overs which was only hinted at, or revealed much more slowly in the book. That's a common feature of most books which become films, however.
You're also right about the downplaying of religious themes. It does remain in the film to some small extent, but the themes are much more explicit in the book.
Overall, a fairly faithful adaptation of the book to film, which is about the best I could expect from a film-maker.