I liked the first part of the book the best. The author tries to link the disappearance of God to the writings of Nietschze and to the Qabalah (parts two and three of the book), but IMHO fails to do anything other than suggest a connection. The book was informative, as far as it went. I would've liked to see the author search ancient religions/beliefs systems/mystical writings for a reason WHY God disappeared, rather than merely speculating on it himself.
Overall, I think it's an interesting read, especially if you like books like The Da Vinci Code.