Leave it to Andrew Klavan, a best-selling author of mystery and suspense novels, to write a spiritual memoir that also manages to be a page-turner. Most readers don’t have itchy trigger fingers for Christian-conversion sagas; you either fire on that frequency or you don’t. But everyone likes a good story, and The Great Good Thing is as dramatic as any tale involving Klavan’s many tough-guy protagonists. In 14 exquisitely wrought chapters, he describes how, raised as a Jew in Great Neck, Long Island, he wound up, at 50, being baptized in a Manhattan church, a believer in Christ.

He grew up “Jew-ish,” as he calls it, the child of secular parents who kept the faith at a safe distance. His mother was repulsed by the rituals of traditional Judaism; she refused the mikvah, the ritual bath given to Jewish brides, and her shame for Jewishness “must have colored everything,” Klavan thinks. Klavan’s father, Gene, cohosted a popular New York morning-radio show. Intense, driven, and suspicious, the father “conceived a special animosity” for Andrew that the son would never fully understand. Their relationship was “one long, furious firefight.”

Whatever their conflicts with Judaism, Klavan’s parents certainly never wanted him to leave the faith—such as theirs was—and become, of all things, a Christian. His road to revelation is long and painful, suffused with a search for meaning, with bouts of depression and rage and thoughts of suicide, but tied together from the beginning by a unifying thread: narrative. Stories run in Klavan’s blood from the beginning. He spins elaborate fantasies throughout his childhood, becoming so “addicted to dreams” that, at age eight, concerned that he is not really seeing the world around him, he disciplines himself to block out his daydreams and take note of the physical world. He succeeds but realizes that trees and sky mean little of themselves; only the mind can give them value.

This moment of acute self-consciousness in one so young is almost difficult to believe, but the more one reads of The Great Good Thing, the more plausible it becomes. Lacking religious faith and detesting Jewish religious instruction, Klavan muddles through preparation for his Bar Mitzvah and endures the ritual, saying prayers and reciting words that mean nothing to him. Afterward, he is showered with gifts, including expensive jewelry, which is placed in a leather-bound box that he keeps in his room. But he grows disgusted with his failure to be true to himself. One night, he creeps downstairs and buries the box, with its treasures, at the bottom of a trash compactor.

The divide between the material and nonmaterial worlds that Klavan spotted as a boy keeps coming back in different forms. He encounters it repeatedly in modernist thinkers ranging from Nietzsche to Freud to Marx. They all have the same answer: physical reality is what counts; whatever we cannot see is mere fantasy. Klavan comes to believe the opposite: that the real thing is what the materialists cannot see—God and God’s love—and that the physical world is its metaphor or reflection. This insight, along with others—he devotes a chapter to five key personal epiphanies—will eventually lead him to belief in Christ.

Yet Klavan’s is a story of a thoroughly secular man, one who attends college just as postmodernism is coming fully into academic vogue and who knows the world of flesh and money and temptation better than most. He spends his life immersed in secular culture; his touchstones are not obscure. They range from Carole King songs to Raymond Chandler novels, from Faulkner to Shakespeare, Dostoevsky to the Bible, Bar Mitzvahs to baptisms; they include the hunger for experience that puts young men on the American road and the uncanny capacity of baseball to throw out metaphors to those same men, older now, when they need them most.

One of Klavan’s writing lodestars not mentioned at length here is William Wordsworth, whom he has written about for City Journal (where he is a contributing editor and I am the managing editor). Wordsworth subtitled his epic The Prelude “the growth of a poet’s mind.” That description is apt for The Great Good Thing as well, which chronicles an intellectual as well as spiritual journey, especially in the chapter called “A Mental Traveler,” in which Klavan conducts a virtual Chautauqua for Western literature and philosophy. He had been a talented but utterly indifferent student, and it is only after he leaves college that he understands what an education really means: “To escape from the little island of the living. To know what thinking men and women have felt and seen and imagined though all the ages of the world. To meet my natural companions among the mighty dead. To walk with them in conversation. To know myself in them, through them. Because they are what we’ve become.” Klavan’s transition from secular man to man of faith is the twin of his earlier transition from cynical intellectual to cherisher of the Western canon. He learns to disdain the bitter if high-flown emptiness of the postmodern project. Anyone who has seen his astute and often hilarious YouTube videos can attest that he knows this enemy chapter and verse.

But for one mystical experience, Klavan travels a road to Damascus free of lightning bolts, coming to faith largely through the language of reason. Freudian therapy even plays a crucial role in moving him along. “It was only when I felt certain that my inner life was healthy and my understanding was sound that I could begin to accept what experience and logic had been leading me to believe,” he writes. “For others, I know it was Christ who led them to joy. For me, it was joy that led me to Christ.”

The mystery of any life’s turnaround is not the results that come from the effort, but the inner light that first prompts the effort. Klavan’s struggle is universal, but his capacities of intelligence, imagination, and will are rare. Even among writers, Klavan’s mission to write four hours a day, every day—which he still does, on old advice from Raymond Chandler—is remarkable, as are the efforts he describes to read the Great Books, even in periods of his life when this required sleeping only a few hours a night. Such willful purpose, such profound engagement with the days and hours, will arouse in some readers the pledge to do better, to spend our own days and hours more wisely; maybe we’ll harvest wisdom or maybe mere efficiency, but we’ll be different for the work, so long as the work continues. Such resolutions often founder, though, on the realization that we remain our same limited selves. Still, The Great Good Thing is the kind of book that sends readers reaching for the light. Whether it’s the light that dwells within us or the light that shines in the darkness—and whether it can be named—are questions all of us have to answer. Even postmodernists.

Paul Beston is managing editor of City Journal.