One concept I hold on to from my Jesuit high school education is sacramentality, the idea that God’s grace is revealed tangibly in our everyday lives in the material world—in small pleasures we can see and name, from the laughter of a child to the smell of coffee brewing, from a favorite time of day to the feeling of a cat rubbing against our leg. 

But if we were assigned to make a list of the tiny joys that brighten our existence, few of us would come up with a catalogue as exhaustive as the purported million-item list compiled by the unnamed narrator of “Every Brilliant Thing,” an affecting play now on Broadway, with Daniel Radcliffe in the lead. His list begins with childlike perennials like “ice cream” and “rollercoasters,” but soon swells to include such niche treasures as “vinyl records,” “the word pumpernickel” and “Christopher Walken’s voice.”

It’s a diverting exercise, in more senses than one. It’s entertaining, yes, but it also literally begins as a diversion from incipient tragedy: Our character starts compiling the list at age 7, when his mother first attempts suicide. Initially he’s hoping to remind her of the many things she has that are worth living for, but as he grows into adulthood, the list-making becomes a way of coping with his own disappointments and depression. As he spirals into a kind of obsession with his swelling list, it begins to seem more like a way of distracting himself from his deeper problems, as if he is pasting colorful Post-it notes over deadly wounds. Indeed, the flip side of sacramentality is that, while we may indeed find signs of God in material pleasures, they are not in themselves God and can lead us away from healing into habit, from salvation into self-indulgence.

If that all sounds like a dose of heavy medicine, it couldn’t go down more smoothly or delightfully than it does in “Every Brilliant Thing.” That’s owing not only to Radcliffe’s scruffy everyman charm, but to the show’s unique construction. Written by Duncan Macmillan with the comic Jonny Donahoe, and since performed all over the United States and the world since its premiere in England in 2013, the play is only technically a solo show, with its lead actor calling on dozens of audience members to shout out items from the list, and relying on a few others to portray major characters in his life in short but significant scenes that are partly improvised. At the relatively intimate Hudson Theatre in New York, Radcliffe interacts most closely with a few hundred audience members seated on the stage around him, but he also runs into the house to interact with the rest of us, even attempting at one point to run through the aisles and give each of us a high five. “The high fives were a mistake,” he admits, gasping for breath. “There are too many of you.”

It’s a funny bit, but it also marks a key turning point in the show. Momentarily depleted by his physical exertion, Radcliffe and his character seem freshly vulnerable. Up to that point he has been playing the audience expertly, even a little self-consciously, as if he’s pulling off a celebrity parlor trick. (Gosh, Harry Potter sat next to me and touched my coat!) But this is a character who is ultimately very much not in control, who needs to ask others for help and for forgiveness, as we all do. For all the show’s interactive romping and horseplay, it is on this nakedly human level that Radcliffe’s heartful performance connects most strongly. 

This is not to dismiss the show’s fourth-wall-breaking crowd work, which requires Radcliffe to work the room, plant ideas and ask audience members for permission for at least 20 minutes before the show starts. (Radcliffe briefly asked me and my seatmate to represent a kindly “old couple” who gave our young narrator a juicebox and candy bar while his mum was in hospital; he told us that we should simply wave and smile at the mention, though a previous volunteer had flipped him off when he called them old.) The effect of all this boundary blurring is powerfully disarming, even destabilizing, and it makes the show’s confessional turn land even more strongly.

If the intimacy and immediacy of theater are its most powerful attractions, the prospect of sitting in a room with all the house lights on, not only to hear a story but to be part of its telling with our fellow theatergoers, can understandably make some audience members nervous. Handled as deftly and generously as it is here, though, it is a happy bargain; in return for giving up some of the usual anonymity of theatergoing, we gain a sense of indeterminacy, even mild danger, within the show’s broad parameters. The whole thing has the effect of waking up our senses, even stirring vestiges of the instinct our narrator cites in the show as, “Fight or flight…or stand as still as you can.”

As he painfully learns, none of those options can stave off disaster. But at least the third, standing still, offers the chance to stop and pay attention—perhaps even pray or meditate, if you’re so inclined—on the world around you, both its small pleasures and its big messes. On the list of things that make my life worth living, I would definitely give theatergoing in general a high ranking, and can now gladly add to it the specific experience of “Every Brilliant Thing.”

Rob Weinert-Kendt, an arts journalist and editor of American Theatre magazine, has written for The New York Times and Time Out New York.