I liked the first book in the series that I think I got for free so eventually I bought this one. Its a little more fantastic than the first one, and a little less plausible, but the book is fun to read, and that is why I read such things.
I don't want to give away a whole lot but the book explains a lot of religious traditions and beliefs in a way that is hard to argue with sometimes.
It mixes magic with religion in a mostly plausible way.
It will probably offend people who are serious about almost every religion out there so if that describes you, it might be best to avoid the book lest you risk offense.