Different denominations may quibble over the particulars, but Sunday morning worship essentially falls into one of two camps.

There's church -- polite, decorous, Miss Mannerly and correct. At the other end of the spectrum, there's chuch: where sweat beads pop and feet slap the floor, marked by random outbursts that rival Whitney and Bobby for sheer drama and a chorus of voices that grab you by the collar, detach your rear from the pew and raise your hands in submission to the heavens above.

In the new documentary "Let the Church Say Amen," it doesn't take long to see into which category the lively World Missions for Christ Church fits. In fact, a recent screening at the National Museum of Natural History revealed that you don't even have to step inside the church's crimson brick sanctuary in the District to feel the power of its ministry.

"Don't give up on Jesus!" Evangelist Josephine Hawkins yells into a car pausing at a stop sign a few blocks from the church. As it pulls away, she shouts a warning at the car's tailpipe: "That car gon' perish one day!"

Director David Petersen and producer Mridu Chandra scoped out hundreds of churches in the District and New York to find the right vehicle to examine the phenomenon of storefront churches, institutions that have stubbornly thrived as much of the rest of the inner city crumbled around them.

"We wanted the audience to feel as if they lived with each person," they wrote in the program notes, "shared their conflicts and joys, and saw the outside world from their perspective."

Petersen and Chandra say the tiny 35-member congregation located at the corner of First Street and Randolph Place NW in the District's Bloomingdale section was an easy choice. As the film crew trailed members throughout 2001, the congregation revealed an extraordinary level of community outreach and member support.

When the filmmakers first approached the Rev. Bobby Perkins -- a onetime crack addict who, along with his wife, Gail S. Perkins, and his sister JoAnn Perkins, leads the 24-hour church -- he didn't exactly jump at the opportunity.

"Coming from the streets and doing the things that I had done, I was paranoid," he told the museum audience after the film screening. But he eventually relented. "I felt in my spirit that the Lord was going to do something greater in our ministry."

That ministry might get greater visibility when "Let the Church Say Amen" airs on PBS sometime next year, but by all measures, the church was doing pretty well on its own.

The film focuses on three members: Darlene Duncan, a single mother of eight with an elementary-school level education studying to become a nurse's aide; David Surles, an earnest father who treats his clients at the Central Union Mission homeless shelter like patrons at the Four Seasons and dreams of buying a home with a yard and a tree.

The third member is Ceodtis "Brother C" Fulmore, a music minister whose son was fatally stabbed during the course of filming, a tragedy that leads him to a faceoff with the Metropolitan Police Department. (Days after the film's Dec. 11 screening, the church had to rally to once again console the grieving Fulmore family: Their 27-year-old daughter was shot to death.)

The film, supported by grants from the Independent Television Service and technical assistance from the Anacostia Museum and Center for African American History and Culture, is Petersen's latest project examining little-known communities.

"Fine Food, Fine Pastries, Open 6 to 9," the 1989 film that earned Petersen an Oscar nomination, was a snapshot of life at the defunct Capitol Hill eatery Sherrill's. His 1996 film "If You Lived Here, You Would Be Home Now," was about art in America from the viewpoint of a small town in Delaware.

Petersen has long admired the tiny storefront congregations that are often housed in corner buildings abandoned by merchants. "They were the anchor of the inner cities," Petersen says. "I felt like I had to take it in really deeply. I wanted to preserve the dignity and uphold that tradition."

Petersen spent many years living in the District near the H Street corridor and vividly recalls the tradition on display during Easter. "The way [the city] comes into bloom, the hats, the clothes, the joy are so manifest," says the director, who now lives in New York. "It's absolutely beautiful and stunning."

This is a stark contrast to the images in "Let the Church Say Amen," where in the shadow of the Capitol, crack fiends nod off on sidewalks on North Capitol Street and drug dealers and prostitutes ply their trades.

For years, the spectacle has elicited sneers from gentrifiers, and indifference from the police. But in the film, World Missions members are shown stepping fearlessly into the mix, passing out literature and urging the forlorn to use the church's resources to turn their lives around.

"Health fairs, health screening, blood pressure, and your eyes, all that good stuff," says Milton Perkins, another Perkins sibling, brightly inviting a man to one of several annual outreach events at the church.

Petersen has a soft touch portraying the young church members. Brother C's youngest son, Cenquan, is a fledgling drummer with deadpan comedic timing. Petersen reveals his optimism in a tight shot of a little girl proclaiming herself "future president" on a white T-shirt.

Then there's the scene in which Darlene Duncan's daughter Qubina, now 12, practices singing a gospel number while her niece Tishjuan Gordon, 9, dances in accompaniment. "When I'm dancing, it's the feeling of flying in the air," Tishjuan explains. "The Lord is speaking to me."

That conviction takes the congregation through all kinds of challenges. Throughout Brother C's trials, his faith never flags. "Everybody on the other side of my voice," he thundered at a community rally with the police department. "Every knee must bow, every tongue must confess. I got faith in my God."

In the film, Brother C ultimately prevails. Yet like many of the triumphs and disappointments at World Missions for Christ Church, his is a victory that is bittersweet.

All of this adds up to a deeply moving 87 minutes that leave you feeling touched, renewed and refreshed -- kind of like a great sermon.

During one evangelical foray pounding the streets, Milton Perkins explains to a woman that the church has free food and clothing for the taking. Eager, she asks him what she has to do to become eligible.

"It's not a thing you have to join," Milton Perkins explains, flashing a smile. "You are already a member."

Darlene Duncan, at left with Joyce Fulmore, is one of the parishioners of World Missions for Christ Church featured in "Let the Church Say Amen."The Rev. Bobby Perkins, left, is minister of World Missions for Christ Church, the focus of the documentary "Let the Church Say Amen." His parishioners include Ceodtis "Brother C" Fulmore, above, who is featured in the film.