Hannia Guillen and Raul Mendez in Bathing in Moonlight at McCarter. (Photo by T. Charles Erickson)

What a title!  Bathing in Moonlight — it’s indulgent, rhapsodic, romantic.  Having now seen Nilo Cruz’s high-minded but often dramatically inert play, I’m puzzled. What is the significance, exactly? Nobody says it, we never see anything that looks like it, and it seems far removed from his central point.

Cruz’s play is about a relationship — an illicit one, between Father Monroe, a Catholic priest (actor Raúl Mendez, in a charismatic but not very varied performance), and Marcela (Hannia Guillen, good), one of his congregants, a beautiful woman from Havana who plays piano in the church (it was once her dream to have a concert career, but straitened family circumstances deprived her of it). Initially, they resist temptation. Will they ultimately choose faith or flesh?  I shouldn’t spoil the surprise, but here’s a hint: Father Monroe was named for Marilyn. (Really.)  Along the way, Cruz provides a few flights of poetic, seductive dialogue. “I’d like to look at you from under the brim of your hat,” Monroe whispers to Marcela. “I’d like to tell you a secret in a dark alley.”

Mostly, though, romance is on the back burner. Bathing in Moonlight is a bully pulpit for Cruz to advocate reforms in the Catholic Church.  His characters (in addition to Marcela and Monroe, they include several members of her family, whose travails provide a secondary plot that never finds focus) argue their points eloquently and earnestly. It’s an admirable idea, but much of the discussion feels like a retread, and there’s little theatrical spark in it.  Bathing in Moonlight comes to life briefly in a few fantasy sequences, where Marcela’s mother imagines her earlier life.  These charming scenes are illuminated by actors Priscilla Lopez and Frankie J. Alvarez.

Priscilla Lopez and Frankie J. Alvarez in Bathing in Moonlight at McCarter Theatre. (Photo by T. Charles Erickson)

But more often, the characters seem to exist to give the playwright a soapbox.  Toward the end, when Father Monroe appears stripped to the waist, revealing an improbably buff, action movie-ready torso, paradoxically we realize how little actual physicality there is in this play, which is meant to be about the thrills and perils of desire.  Director Emily Mann’s production is sleekly staged, but doesn’t suggest much inner life.

There’s no doubting the sincerity and good intentions of Bathing in Moonlight.  But it registers more as a position paper than a play.

Bathing in Moonlight runs through October 9. For more information, visit the McCarter Theatre Center website.