It seems that the creator of Dilbert is obsessed with religion and how it controls humans, a feeling I can relate to. Many believe that religion and bible-like books are the effects of smart people trying to improve humanity with stories (give and you shall receive).
In the book, he makes a fairly believable connection between god and the big bang (hence, god's debris) to bridge the gap between religion and science and also between different religions (all religions are looking at the same thing from different viewpoints).
Some parts I was less enthusiastic about like the notion that evolution must appear in big jumps and does not, and so it might not be real. I don't think evolution must appear in big jumps, I think the opposite, many small changes lead to big changes over a long period of time. Wings appeared after years of jumping animals that jumped farther and farther thanks to bigger and bigger membranes under their arms and eventually became wings.
He adds touch of "How to win friends and influence people" when he write things like "Yes, that is the essence of being human. Any person you meet at a party will be interested in his own life above all other topics." to teach us some good.
All and all its written very well, and might actually change some people's minds and do good.
You can read the book for free here: http://nowscape.com/godsdebris.pdf
I'll probably read the sequel: The Religion War (couldn't find a free version)