Nearly 200 years ago a circuit pastor named Ezekiel Cooper stopped in the tiny community of Oxon Hill to preach to the area's white residents--the land owners, merchants and farmers. To Cooper's surprise, a black man approached him after the service and, with head bowed, asked him to preach to the slaves that evening. Cooper agreed.

"Their society is very numerous and very orderly," the preacher noted in his journal after his sermon. "And to their great credit, with pleasure I assert that I never found a white class so regular in giving in their quarterage as these poor people are, and the greater part are slaves, of whom never request anything."

This month that congregation of Methodists, believed to be the oldest in the nation, celebrates its 190th anniversary. To mark the occasion St. Paul's United Methodist Church -- now a thriving fam- ily of 240 -- is sponsoring lectures, fish fries and fairs.

They also have chosen a theme: "We've come this far by faith."

Since Ezekiel Cooper's infrequent visits to Oxon Hill, the members of the modest, white-frame-and-stucco church have faced -- and overcome -- many obstacles. In 1863, slave owners seized their meeting house and forbade further assemblies. In the 1920s and '30s racial discrimination was so pervasive in Oxon Hill that only a handful of blacks who lived near the church came to worship there. Always plagued by financial difficulties, St. Paul's was run-down and dilapidated throughout the 1950s and '60s. To the congregation, the church's anniversary this month represents the rewards of endurance. Today St. Paul's has a large, well-educated and financially solvent membership. The church recently was renovated and refurbished. As the size of the congregation increases -- 50 new members have joined in the past year -- so does the institution's confidence, ambition and spirit.

The key to St. Paul's success, members say, is that it "instantly accepts" newcomers. "You don't have to belong for 20 years before you're a part of the group," explains Clarence Miller, a seven-year member who heads the Sunday school program.

He adds, "We've been very successful in a period of transition."

In the past 10 years, Oxon Hill has gained 30,000 new residents to put its present population at 62,882. But the community's most remarkable change has been in the number of black residents. Some 4,000 blacks lived in Oxon Hill 10 years ago, but today, as more and more blacks are able to afford the area's new housing, that number has reached 32,000.

Church administrators say most of the new black residents are Methodists or Baptists.

The population growth has brought a new kind of worshipper to St. Paul's. Church elders boast that their congregation now includes government employes, military personnel, doctors, lawyers and other professionals. More than half have college degrees and several have gone to graduate school. Currently, 12 members are attending college. What does this mean for "the little church by the side of the road," as the Rev. Albert Moser likes to call St. Paul's? "We must reach out to those less fortunate than we are," Moser exhorted the congregation during a recent service. The church each year offers one of its high school seniors a $1,000 college scholarship, and as a part of the Health and Welfare Ministry of local churches, sponsors counseling, gifts of clothing and loans to some of the area's poor blacks. But, Moser said, "We have only done just a little bit. We haven't come close to doing half of what our Lord would have us do to help."

"Some of us now have our own fields and our own large houses," Moser said, recalling the days when St. Paul's was a slave congregation. "We must not forget from whence we came."

Moser says that despite its recent growth and improved finances, St. Paul's is still in touch with all members of the church community, rich and poor, educated and not. "We are the little church by the side of the road. We take that quite literally," he said.

Indeed, St. Paul's stands beside St. Barnabas Road, just over the Prince George's County line and next to an ancient cemetery. Across the street is a white clapboard structure, Oxon Hill Baptist Church.

Along with numerous church-related organizations -- the administrative board, the trustee board, the United Methodist Men and the United Methodist Women -- St. Paul's has two "historians." Eston and Thelma Tanner, members of the congregation for 55 years, can remember when the church had just two dozen worshippers during the 1930s. Back then, Eston Tanner says, "Oxon Hill was just like any little Tennessee or Alabama town."

Thelma Tanner recalls that during the 1960s, a turbulent time for blacks across the country, St. Paul's was headed by its first and only white minister, the Rev. John A. Shirkey. Socially and politically active, Shirkey led St. Paul's members through several peace marches and organized aid to black families who had been "burned out of their homes" during the riots in Washington. "I don't think we'd made so many peanut butter and jelly sandwiches in our life," she laughs.

There are also memories of more recent times. Thelma Tanner produces a photograph, taken just five years ago, of a square gray cinderblock building with an overgrown lawn. "It wasn't so long ago that St. Paul's was three buildings, all unattached, made of cement," she said.

In 1979, a $28,000 boost changed that. The United Methodist Union, a part of the Baltimore Conference of United Methodist Churches, gave St. Paul's $5,000 and a $23,000 loan, under a program designed to help the growth of small ethnic and minority churches.

One of the first things the congregation did was to join the three small buildings that had housed the church, its community room and its Sunday school. In short order came a stucco and paint job for the church's exterior, new furniture, pews, carpeting, a kitchen and bathrooms. To get maximum use of the money, church members contributed their time and efforts to the renovation "out of sheer love for this little church," says anniversary committee chairman Cora Marshall.

"That's the special thing about this church," said lay leader Ralph W. Young. "We never had all the resources to do what needed to be done. We were always short on money but, by some hook or crook, it got done.

"It got done because of faith," he said. "I don't know what else could have done it."

With its educated, middle-class congregation, has St. Paul's become a political force in Prince George's County?

Congregation members say yes. Candiates frequently speak at St. Paul's, and two church members who are voter registrars often advise parishioners on how to cast their ballots.

"Historically, the black church has addressed political issues," Moser said. "St. Paul's is a forum for discussion of housing, education and other political issues."

But many parishioners see St. Paul's not as a political or religious center, but as a home.

"I just moved to the community two years ago," said Cecil Hopkins. "I was raised in my church in Bluefield, Va. It was a small town -- about 5,000 people -- and in our church there was friendship and warmth." He smiles. "I found that here in St. Paul's. When I first came here, I felt like a young man again. I felt like I had found a home away from home."

Wallis Stephens, director of the United Methodist Men, called St. Paul's "a family." "The key to St. Paul's is that we trust each other," the former Marine said. "You can't find that anywhere else."

Older members of St. Paul's often quote the anniversary theme -- "We've come this far by faith" -- to express their devotion.

"This church is old. It shouldn't have survived, but it did, and that means a great deal," said church member Alexander Faison.

St Paul's "keeps our children in touch with our black heritage," he said. "With the exit of blacks from the District, kids were losing their black identity. This church affords our children the chance to experience our heritage."

At 190 years old, "This church meets our needs," he said, "From here, we can see where we came from, and where we are going."