Cass Buggé, Kerstin Anderson, Virginia Kull (kneeling), Luisa Sermol, and Lucas Near-Verbrugghe Photo by Kevin Berne

Despite the strictures of their upbringing, the kids seem to have strayed far off the path of righteousness, at least as determined by the elder Dahls' faith. Johnny, the youngest (and always last to arrive for Christmas celebrations), is a recovering heroin addict who has brought along one of his AA sponsees, Loren (Vero Maynez), who is 126 days clear of an Oxy addiction. "What's Oxy?," one of the siblings asks. "It's heroin you get from the doctor," Loren replies.

Then there's Mark (Lucas Near-Verbrugghe), who has never quite lived up to his parents' expectations (after Harvard Law and a Supreme Court clerkship, he took a quiet government job) but still maintains a faith in God, while also claiming he's "not a Christian anymore." Evie (Virginia Kull) may have veered furthest from the path her parents set for her: she's a lesbian who has recently married Pippa (Cass Buggé), who is expecting the couple's first child.

The only child who seems to have retained her faith is Diana (Kerstin Anderson). She has, in fact, more than retained it–she has turbocharged it, claiming to be a channel through which God speaks, which leads to some uncomfortable exchanges with Evie when she tries to convince her gay sister that "I know the spiritual truth that this is not what God wants for you."

The cast is uniformly excellent, playing off of each other like members of a tight, well-rehearsed band. Which is fitting, as the family is a musical one, and the show is filled with music. Dad plays piano, as does Johnny, Mark plays guitar, Evie's ax is the ukulele, and they all sing quite well.

But the real star here is the teaming of playwright Leslye Headland and director Trip Cullman. Headland's script is dense with humor, insight, pathos, and a deep understanding of how families communicate. It can be too dense at times, with multiple characters speaking over each other–which got me thinking how interesting this play would be if it were an immersive, interactive theatrical experience, where the audience could move from room to room, watching dad work out his anger in the kitchen all by himself, or to go upstairs with Evie and her husband James (Christopher) to check on their crying baby, or to walk around the dining table once dinner has been served (after Johnny finally arrives) and pick up on all the individual conversations happening.

Cullman has made great use of an amazing set, by scenic designer Arnulfo Maldonado, that re-creates a quintessentially middle-class American home at Christmas. We see the entire downstairs: living room with fireplace, staircase upstage, dining room and kitchen stage left, and frost-covered windows with a gentle snow falling outside. There's always action somewhere on stage, and Cullman–in collaboration with his cast–has made every interaction feel like true dysfunctional family dynamics. The hugs, the turnings aside, the retreats to either side of the house–it all feels like you're watching a real family in crisis. And with addictions (mom fills a punchbowl with Manhattans!), zealotry, spousal bickering, and long-simmering tensions coming to the fore, it's a non-stop crisis–that also happens to be very funny. When Loren, the newcomer, brushes off the family's spatting, saying "I OD'd last summer, so this is pretty tame," mom Ginny immediately quips back, "Give it time."

Despite the very naturalistic humor–no setup/punchline jokes here–there are some wonderfully deep insights, as well. When she is asked about her feelings on God, Loren, the recovering addict, states that she can "get the idea of a higher power. Like gravity." She then goes on to explain how she sees its effect, may not understand fully how it works, but likes that it doesn't try to shame her. And there is a blistering moment when Rachel, Mark's wife who converted from Judaism for him, tells Diana and James "On the day of judgment, you will see. He will not know either of you."

Over its 100-minute, intermissionless running time, Cult of Love manages to cover a wide range of family dynamics, both the good and the bad. In one moment, the kids will be spatting with each other or with their parents, and then someone will pick up a guitar or sit at the piano, and suddenly the family is united in song, each playing their own important part–culminating at the show's end with a gorgeous close-harmony rendition of "Shenandoah." It's a heartwarming end to a heartrending comedy about a family struggling to stay one.

Cult of Love runs through March 3, 2024, at Berkeley Repertory Theatre, Roda Theatre, 2015 Addison Street, Berkeley CA. Shows are Tuesdays, Thursdays, Fridays and Saturdays at 8:00 p.m., and Wednesdays at 7:00 p.m. Matinees are Saturdays and Sundays at 2:00 p.m. Tickets range from $22.50-$134. For tickets and information, please visit www.berkeleyrep.org, or call the box office at 510-647-2949.