The book tells the origin of the god Om, and his relations with his prophet, the reformer Brutha; in the process Pratchett satirises religion, religious people and practices, and the role of religion in political life. Omnianism bears a resemblance in some aspects to other monotheistic religions, particularly Islam and Christianity. While the dominant tone is cheerful cynicism, the author concludes on a spiritual note.  The character of Vorbis is one that may interest any reader interested in questions regarding institutional religion, heresy, and the direct communication between God and Man. Vorbis has a reputation for being a man touched by destiny (and 'perhaps something else') and as being one of the most devout Omnians in the Empire ('Vorbis could humble himself in a way that made the posturings of power-mad emperors look subservient') yet in the end the reader finds that the only voice Vorbis has been listening to is his own.  This book is the source of some controversy among Discworld fans, as they cannot decide whether it takes place 100 years before all the other books, or takes place in the same timeframe save for the ending, which is 100 years after. Pratchett himself has never really clarified the issue, and indeed seems to get some amusement out of deliberately not answering. Something of an explanation was provided in Thief of Time, where it is suggested that two centuries became enmeshed during that period, and so the question is actually unanswerable. Death, however, had a clear time frame of it, mentioning in Thief of Time that the prophet Brutha proved a chapter of the Book of Om to be a metaphor a hundred years ago. It is worth noting, however, that in Carpe Jugulum, a discussion between Omnian priest Mightily Oats and the witch Granny Weatherwax suggests that the events took place several generations ago. In addition, a number of the Discworld books feature Constable Visit, an Omnian-turned-policeman; if the events of Small Gods had happened in a similar timeframe to the other Discworld books, Constable Visit's presence would have been dubious. However, Small Gods features some philosophers that also feature in the book Pyramids, and Pyramids features the same head-of-the-assassins-guild as Men At Arms, implying that it does indeed feature in the same time frame as some of the other books.

A very interesting and rather one track story about the nature of philosophy and belief and an examination of religion becoming more about the heirarchy than the faith. Vorbis is a run of the mill Discworld bad guy, utterly selfish, without morality and totally under the belief that he is absolutley right all the time. Brutha is a more worrysome individual, he's never questioned his belief and when he does so he finds that his faith is all the stronger for it because he does believe in the basic goodness of humanity and that by doing the right thing he's able to do extrodinary things, even standing up to Om when necessary. It's a pity it's a one off book, there's definetly room for a sequel...