The Godmakers by Frank Herbert

It is the far future and a space-faring humanity is beginning to rediscover planets settled before the devastating Rim War. Their greatest fear is another war, so each time an occupied planet is found, any warlike tendencies lead to a corrective occupation. Particularly prized are the rare individuals with psi powers, which are better understood than now and whose development is largely linked to religion: properly channelled, psi powers can create a god.

Lewis Orne is a newly-trained member of the Rediscovery and Re-education Service, whose job is to assess the cultures of newly-found settled planets to determine their suitability for joining the Galactic Federation. While he is demonstrating remarkable ability in tackling one intractable problem after another, the Abbod of Amel, the planet which is the focus of human religion, is creating a god: exactly what and where, he has no way of telling.

Orne suffers a near-death experience which affects his outlook on life. On recovering, he discovers that he has psi powers, and is sent to Amel, where his process of self-discovery reaches a remarkable conclusion.

Herbert wrote this book after Dune. It is a much shorter work (175 pages in my 1974 NEL paperback) without the same epic sweep. Nevertheless, it reflects the same fascination with the techniques of myth-making and religion. I can recognise certain elements here which must have subconsciously influenced me when writing Scales, particularly the effect on an individual of the development of unusual abilities. However, Herbert focuses more on the process of getting there than on what happens next. It isn't a great book, but it's worth the time to read.

(an extract from my SFF blog)
That's a judgement call, I think. Obviously, any copying of text is straightforward plagiarism, but most themes and plot devices are not original. What matters is that you should find an original treatment for them.

Just think of those zillions of Mills & Boon romances. They basically have one plot; attractive unattached female finds Man Of Her Dreams. There is some complication or falling out which means that they part, but at the end of the book they get together to live Happily Ever After.

In SFF, you've got all those books about special relationships between people and the dragons they ride. And magic swords. And humble boys/girls who turn out to have magical powers. And so on, and so on...
I really liked The Godmakers, though I do wish it was a little more fleshed out. However, some of the themes of the book did end up in the later Dune novels.