Brown's novel is full of science, mystery, and religion.
The crux of the novel involves a conflict between science and religion. You have Maximillian Kohler and his hatred for organized religion, namely the Roman Catholic Church. Kohler's the director of CERN, a physics laboratory, and has their latest discovery, that of antimatter, stolen.
Of course, the antimatter will be used against the Roman Catholic church.
The novel also explores religion in how it attempts to get inside the catholic church and the inner workings of the Vatican. Look at the text again and examine the controversy over electing a new pope and the scandal that is perpetrated as a result of that.
In terms of mystery, look into the illuminati, the secret society that plays a major role in the book.