When a play begins in a hospital waiting room, the audience may instinctively brace itself for a story it has seen countless times. When a play presents two gay lovers, one Christian and the other atheist, the audience may lick its lips for a meaty philosophical debate with a modern twist. When a play does both, certain cliches lock into place that lead the audience to think it knows exactly what kind of story will follow.

Despite such conventions, the Geffen Playhouse’s newest production “Next Fall” offers a sad, yet hopeful meditation on the way people’s obsession with overarching life philosophies often distracts them from the life they are living – a message the audience may ironically (or fittingly) miss if it becomes blindsided by its own premature assumptions about the play.

“Next Fall” begins with a jarring orchestral recreation of a car crash that lasts no more than 10 seconds before hot blue spotlights burst to reveal two silhouetted figures in a New York City hospital lobby. Brandon (Ken Barnett) and Holly (Betsy Brandt) fidget as they wait for news of their friend Luke’s (James Wolk) surgery. Luke’s mother (Lesley Ann Warren) teeters into the room as though propelled by a gas tank of amphetamines. Her chatter is meant to be optimistic, but it feels out of place.

“Next Fall” moves slowly, often failing to clearly explain the relationships between characters. When Luke’s boyfriend of four years, Adam (Geoffrey Nauffts, also the playwright), sweeps onto the stage, his presence feels unassertive and vague, leaving the audience to question his attachment to Luke.

Flashbacks change all of that. The play’s non-linear handling of time dips smoothly into past and present, but doesn’t hinge on shocking last-minute revelations. On the night they meet, Adam is a self-effacing 40-year-old candle salesman, and Luke is a young waiter and aspiring actor who not only performs the Heimlich maneuver on Adam, but also has the confidence (or naivete) to admit that he did it just so he could hold him.

The idyllic afterglow of the couple’s first morning-after shatters when Adam catches Luke praying before a meal. An unapologetic atheist, Adam interrogates Luke about his beliefs on the afterlife only to receive some hard answers.

While disguised as a tragedy about two men with irreconcilable views of the world, “Next Fall” has nothing to do with God or science. It portrays Luke as a big-hearted man whose faith both protected him against his mother’s absence and held him close to his doting father, Butch (Jeff Fahey), a gruff Tallahassee native with an affinity for homophobic and racist slurs .

For all his epithet-hawking, Butch emerges as a sympathetic character. Played flawlessly by Fahey, Butch buries his beliefs so he can tell Luke that he acted brilliantly in “Huck Finn,” ignore Adam’s provocations on the topic of evolution and sit in a waiting room with the woman who abandoned his son. At the end, Fahey alone bears the most heartrending scene of the play.

Only after it ends does “Next Fall” appear deceptively simple and sincere. But its initial promise of intensity turns lukewarm with conversations that last too long and mild attempts at commentary on religion that never quite go anywhere.

For all its understated seriousness, “Next Fall” has an incredible sense of humor – at times dry or caustic, while at other times jokes feel clipped out of a guilty pleasure sitcom. Regardless, laughs abound.

Sure, “Next Fall” insists on a set-up that one may foggily recall from some “Grey’s Anatomy” episode. Sure, the story of lovers with warring belief systems feels pre-Homeric. But “Next Fall” dares the audience to reject its preconceived expectations at the risk of missing out on the play’s message. The play neither pontificates, nor holds a political agenda. It is not about left versus right or gay versus straight.

It is about how people exaggerate the importance of those oppositions and sacrifice love in the process, but it is also about learning the lesson that while next fall might never come, the certainty of the here and now can (and will) suffice.