Thirty years ago I was browsing a secondhand book sale in the basement of the divinity school where I teach. There was a folding table covered with worn-out books, arranged in no order and at giveaway prices. I was drawn to a devotional book by the British author and preacher Leslie Weatherhead, whose books on faith and psychology had achieved enormous popularity in the decades after World War II. The book was called A Private House of Prayer, and it had a gold cross embossed on the cracked leather cover. The book is a liberal Protestant’s version of Teresa of Ávila’s Interior Castle. It is divided into seven rooms of devotion, each signifying a distinctive mode of prayer. It begins with affirming the presence of God in room 1 and ends with meditation in room 7 at the top of the house.

Once I had the book in hand, what caught my eye was the name written inside the cover, that of Jim Cleland, one of my predecessors on our faculty and longtime dean of the university chapel. His sharp wit and Scottish brogue made him one of the most beloved persons ever to serve the university in any capacity. His most famous sermon was “Blessed Are the Debonair.” Jim died on the day I interviewed for a faculty position, so we never met. As I looked through the other books on the table, I realized they were all Cleland’s books, but A Private House of Prayer was the most personal one of all. It seemed to me that such a book had no business on a sale table. So I bought it.

When you buy a used book, it’s like joining a conversation in progress. You are learning not only from the author but from the book’s original owner, and the three of you form a small, silent symposium. The used books I order from Amazon for $.01 plus shipping often come with personal endearments and messages of encouragement written on the title page, as well as sage and not-so-sage comments scrawled in the margins, all of which now belong to me.

Cleland’s book was meticulously underlined and annotated. He had obviously used a straight edge and underlined only in red pen. At the end of the chapter on giving thanks, he had made a list of those for whom he was thankful, including his wife, Alice, other family members, friends and the name of his school. It was an unspoken invitation to add a few names of my own.

When I bought the book, I could not have known that I would lose track of it for 20 years, only to rediscover it just in time to give it to my son to read in his final illness. Who would have guessed that a smart young lawyer would treat an old book of prayers as found treasure and add his own markings in messy pencil?

I could not have predicted how the goodness of this book would skip a generation and bless my son.

He often gave me books, usually inscribed with a personal message from the author that he himself had forged. I gave him books as well, and now they have come back to me as my inheritance. They too are covered with his pencil scratchings and notes to himself, which are now notes to me.

There must be a moral in all this: one might caution against trading a tear-stained page for a Kindle or Nook, but these electronic devices can come in handy, especially on airplanes or under the covers. Or one could invoke several sayings on the brevity of life, each one more depressing than the next: Sic transit gloria mundi. Or perhaps “Art is long, life is short.” That is, books outlast people. But that isn’t true in every case. I’ve outlasted several of my books.

I choose another lesson, which is the gospel of used books: there is a grace that can work through a book even when the book is out of print, its prose has become an acquired taste, its author is forgotten, and the whole world has moved on to something new. The DNA of the book remains. It passes from hand to hand with the usual signs of age—and love—still intact.

We don’t know what a dog-eared Kindle looks like—at least, not yet. But if they can figure out how to make it bend and crack without losing its capacity to touch the human heart, it may one day be as good as a book.