Gilead is a wonderful, precious book. I loved reading it and I’d urge it on anyone. But it isn’t an easy sell. From the outside, it looks austere, quiet, maybe even dull, and I pity the blurb writer who first had to try to encapsulate this story of a 76-year-old cleric from Gilead, a small (very small) town in rural Iowa, writing to his young son and looking back over a long life lived mainly alone and in prayer. It is a novel that defies summation. The crucial experience comes in engaging with the voice of the Reverend John Ames; entering his world and his heart. There’s plenty of gentle wisdom:

“A man can know a thing to death and be for all purposes completely ignorant of it. A man can know his father, or his son, and there might still be nothing between them but loyalty and love and mutual incomprehension.”

There’s sly humour:

“But I’ve developed a great reputation for wisdom by ordering more books than I ever had time to read, and reading more books, by far, than I learned anything useful from, except, of course, that some very tedious gentlemen have written books. This is not a new insight, but the truth of it is something you have to experience to fully grasp.”

Most of all, there’s a sense of bright, piercing joy, found in sharp and beautiful passages. Robinson shows us the world anew; to watch a child play with their mother is a lovely thing, but through the eyes of John Ames, this obvious joy seem all the clearer and fresher, as he observes his son, wife and cat playing with soap bubbles:

“Some of the bubbles drifted up through the branches, even above the trees. You two were too intent on the cat to see the celestial consequences of your worldly endeavours. They were very lovely. Your mother is wearing her blue dress and you are wearing your red shirt and you were kneeling on the ground together with Soapy between and that effulgence of bubbles rising, and so much laughter.”

It doesn’t seem like much – but this moment also seems to encapsulate everything that matters. As Ames says: “Ah, this life, this world.”

This voice cast such a persuasive spell that it was only after finishing the book that I even thought to question if pastors in 1950s Iowa really would have thought and written like Ames. But I decided I wasn’t too bothered about historical accuracy. It felt right. That’s what counts.

Of course, I’m not the first to wonder how Robinson wrote Gilead – her answer (to fan Barack Obama) is both as elusive and revealing as you might hope: “I was in this hotel with a pen and blank paper, and I started writing from this voice. The first sentence in that book is the first sentence that came to my mind. I have no idea how that happens. I was surprised that I was writing from a male point of view. But there he was.” Speaking to James Naughtie on the Radio 4 book club, Robinson added another fascinating aspect of this near-magical process: “He presented himself to me as a good man.”

Is Ames really as good as he wants his readers to think he is? That’s the question that elevates Gilead beyond just beautiful prose. Generally, Ames is a lovable presence, and Robinson herself has said she finds it more interesting to write about good people than bad. But that doesn’t mean that the character is without complication. His views are not always palatable – as with his thoughts on the flu epidemic at the end of the first world war: “Their deaths were a sign and a warning to the rest of us that the desire for war would bring the consequences of war.”

As the book goes on, we also learn of Ames’s complicated relationship with his best friend’s son and his namesake, John Ames Broughton. As Ames ponders how much he should say about the wrongs Broughton may have committed in the past, we wonder how fair he is being. But here I should pause. As Ali Smith wrote in her review of Gilead: “To say more here about the story would be to rip through something Robinson takes care to deliver with spider-web fineness.”

She is absolutely right. The slow, delicate spinning out of this mystery is one of the book’s several marvels, so let’s save it for next week. For now, I just want to say again that if you haven’t read Gilead already, you really should.