The Godmakers by Frank Herbert
Our protagonist, Lewis Orne, agent for the Investigation-Adjustment Bureau, visits four different planets in order to ascertain whether they are a threat to Galactic peace. On the way, his latent psi powers become active and he finds himself in a tricky situation on the final planet, where he finds he could very well be considered a God.
Although published in 1972, this novel is a fix-up of four short stories published between 1958 and 1960 in the pulp science fiction magazines Astounding and Fantastic, and it shows in the writing. The female characters are treated in the usual pulp fashion, falling in love with the hero five minutes after meeting him, or acting as the power behind the throne to male characters in positions of power (because a female government or military leader would be unthinkable.) Humans are, of course, superior to any alien race our hero comes across, and it is his duty to civilise them.
There is not much connecting the stories, other than the recurring characters and their ongoing mission to keep the Galactic peace — the book would have worked just as well as an anthology collection of the individual short stories.
Not recommended if you are looking for an enthralling, novel length story. One for the pulp enthusiast only.