"The Gates of Creation" by Philip Jose Farmer
"...the Lords have inherited their weapons. What they haven't inherited or taken from others, they cannot get. The race has lost its ancient wisdom and skill; it has become users, consumers, not creators. So, a Lord must use what he has. And if these weapons do not cover every contingency, if they leave holes in the armor, then they can be penetrated.
"There is another aspect to this. The Lords fight for their lives and fight to kill each other. But most have lived too long. They weary of everything. They want to die. Deep in the abyss of their minds, below the thousands of strata of the years of too much power and too little love, they want to die. And so, there are cracks in the walls."
"The Gates of Creation" is the second book in Farmer's World of Tiers series, and was first published in 1966. I have yet to read the other books in this series.
The novel is centered around Robert Wolff, also known as Jadawin, a member of a race called the Lords. The Lords are godlike beings, who maintain their godhood through technologies others have invented. The Lords, powerful enough to remain virtually immortal and to create entire universes, lack the scientific understanding upon which their technologies are based. Their machines allow them to do wondrous things, but they are like children playing with toys, unconcerned with how their actions influence others.
The Lords perpetually war against one another, and all seek to overthrow their father, Urizen, who sits over and above the World of Tiers they have created. Urizen sets traps for his children, and delights in pitting one sibling off against another.
At the beginning of the novel, Urizen abducts Wolff's concubine, Chryseis, and forces Wolff and several other Lords into an open confrontation. Early on the Lords are deprived of their miraculous devices, and must rely upon Wolff to lead them. Wolff, having learned much from a brief stay on Earth, possesses a practical knowledge that all of the other Lords have lost.
In tone, the novel resembles a Robert E. Howard story, with bits of "science" thrown in for good measure. The characters are all lustful and larger than life, and the action flows seamlessly from beginning to end. It's definitely not the deepest sci-fi novel I've ever read, but I never felt like it was boring. It's a lot like reading a video game, with each chapter representing another level of the game.
I plan on reading the other books in this series, and I enjoy Farmer's more sexualized take on the science fiction genre. While "Gates of Creation" won't blow your mind in the way that "God Emperor of Dune" or "Lies, Inc." will, it offers a well-written adventure story, highlighted by gods who are engagingly human.