Krista Kurtzberg, playing Sister Mary Leo, in the production of Nunsense put on by the Maine State Music Theatre at Portland Stage. Credit: Maine State Music Theatre photo by Aaron Flacke

Confession time: “Nunsense,” currently in joint production with the Maine State Music Theatre on the Portland Stage, is a thoroughly engaging and hilarious show that even heathens will enjoy.

Before the action begins, audience members unfamiliar with “Nunsense” may wonder if they’ve bought tickets to the wrong venue; the stage is dressed with the set design for a high school performance of “Grease.”

Designer Anita Stewart even matched the bilious green ceramic tiles and painted trim of those hallowed halls. But then Kimberly Chesser as Sister Robert Anne introduces herself and explains that the sisters are at the high school to put on a fundraiser. And so the revue begins, a mix of song, dance, and Catholic humor that made even the large group of attendees from Amish country laugh loudly and often.

The premise of “Nunsense” is that five nuns are hosting the show to raise desperately needed funds. They need money to bury the last three of 52 sisters accidently poisoned by their own cook. For the moment, the dearly departed are in deep freeze in the convent kitchen’s freezer, and the New Jersey Board of Health is near to knocking on the priory doors.

The cassocked quintet on stage represent the few convent dwellers left alive to lay them to rest. But they need money, so the surviving sisters have been pressed into service to put their — to Mother Superior’s mind — questionable talent to work entertaining the public while collecting coins in their coifs.

Credit: Maine State Music Theatre photo by Aaron Flecke

As the show moves along, each sister adds her take on performing, on being a nun, or — in Sister Mary Amnesia’s case — trying to remember life before taking vows.

The script might put Mother Superior through a few crises of faith about the talents of her remaining charges, but there can be no doubt about the manifold talents on view at Portland Stage. Veteran actor Mary Stout, as Sister Mary Regina, Mother Superior, rules the stage as she rules the convent by sheer force of personality and presence; she has no need for the ruler she wields.

Witty Tamara Anderson is Sister Mary Hubert, Mother Superior’s right hand who gently intercedes for the younger nuns while keeping their leader in check with teasing barbs.

Chesser lays the Brooklyn accent on thickly enough that one can almost hear the gum-cracking habit the nuns probably beat out of her when she became Sister Robert Anne.

Krista Kurtzberg plays petite Sister Mary Leo, a former ballet dancer who aspires to wow the audience with her plies and jettes but it’s clear she’s found her calling.

Rounding out the cast is Jeanne Tinker who shines with heavenly light as Sister Mary Amnesia, new to the mission and, as her name implies, unable to remember how she got there after a crucifix fell on her head.

That type of delicious dark humor fills the show. Depending on seating or technical issues, it was sometimes difficult to clearly hear all the rapid-fire jokes and witty lyrics over the audience guffawing. Laughter may not get a person into heaven but it certainly makes life on Earth more enjoyable.

It may be a bit shocking, for those who attended Catholic school, to see the quintet tap dance across stage — in sensible shoes! — but a familiarity with Catholicism or Christianity is not necessary to enjoy “Nunsense.”

“Nunsense” by Dan Goggin, directed by Teri Gibson, runs at Portland Stage, 25A Portland Ave., Portland, until Sept. 9. Purchase tickets online or call the box office at 207-774-0465 for more information.