Winner of the 1968 Hugo Award for Best Novel. It was also nominated for the Best Novel Nebula Award. The winner was “The Einstein Intersection by Samuel R. Delany.A combination SF/Fantasy about a ship from Earth, The Star Of India, that lands on an alien planet. In the far future the crew fashion themselves as Hindu gods who keep the passengers/colonists in a non-technological era.
The book is mostly flashbacks relating the experiences of Mahasamatman, a rebel crewman who prefers the name Sam. He’s also called Buddah, Siddharta, The Lord Of Light etc. as he starts a new religion based on Buddhism. The natives of the planet are called demons. They’re energy beings and have been locked up in Hellwell. The Earth crew are now able to move to other bodies. They create a Hindu caste system with themselves at the top. They’re called “Firsts.”
Human society discovered the printing press three times but the now gods have denied any progress to them. Sam is an acelerationist who wants society to progress. The gods want to keep their decadent lifestyle and violently oppose him. Sam’s journeys take him to Hellwell where he frees the head “demon.” They end up sharing a body. The battle is on in Heaven.
The gods have a big problem with Sam. He won’t stay dead. The battle for control of the world goes on. There’s a thread of humor in all this including one god’s fascination with a new invention that’s actually a toilet. The flashbacks go on for several stories before coming back to pick up from the end of chapter one. The final two battles are very well written.
It’s not a book to hurry through and may even take some re-reading but it’s worth sticking with.
Vintage45's Blog 
My second favorite Zelazny work — This Immortal being my favorite…. Nice review 🙂