Arthur C. Clarke's Third Law states: Any sufficiently advanced technology is indistinguishable from magic. This book is based on a similar premise: Any being with sufficiently advanced technology is indistinguishable from a god.
The book was the winner of the Hugo Award for best novel in 1968. An interesting mixture of science fiction and Hindu and Buddhist mythology, it is never really explained where or when the events happen.
I found it an interesting concept, but I didn't fully buy into it and didn't find any characters that I really liked or felt that I understood. I found it rough going to get through, despite being extremely well written and very poetic in places.
It is an interesting and imaginative concept that defies categorization as science fiction, fantasy, or something else.