WHEN we look back, O Lord, sometimes we have to wonder why we have a roof on our heads. When we look back, O Lord, we have to wonder why we have food on our tables. Thank you, O Lord." The deacon is revving up the motors of prayer. The hands of the clock are just inching past 11 a.m. His pastor, the Rev. Frank Tucker, has yet to swing his arm across the pulpit's invisible web of unwanted presences to signal that the prayer is being felt. The connections are just beginning.

"Thank you for another chance, O Lord," the deacon continues. A "thanks" echoes back from the row of gravelly male throats that is the deacons' hierachy. "We just hop this chance will not be in vain," adds the deacon. "Well," urge his solemn echoes.

Another Sunday morning begins at First Baptist Church. In the 117 years of its existence, which was celebrated this week, no one remembers a Sunday of worship missed. This is through the terrifying flight of the founding members from slavery in Virginia, through Reconstruction encampment in muddy government grounds in Southwest, through a half-century of painful upward mobility as those slaves built homes, churches and schools in what because the thriving neighborhood of Southwest, through the post-World War II uprooting of that area to a once-Presbyterian location at New Hampshire and Randolph NW, through the mortgage burning and the scrapping of Sunday suppers to the brown envelopes of the tithe, and to contemporary status as a full-service community anchor.

First Baptist Church, a granite landmark off the hub of Georgia Avenue, is thriving, despite the noticeable apathy among younger blacks toward organized religion, despite the recesion whipping that limits the budgetary generosity of most black families, despite the activism offered by professional groups that have opened up for blacks, despite the competitions of cartoons and news panels in that 11 a.m. hour.

For generations the black Baptist church in America was a shelter and a guidepost for many blacks' spiritual and social needs. In critical times it provided the heart and energy for protest. In more recent years, it has been looked upon as a time capsule of old values and ideals: The men ruling the church, using their structures, visibility and rolling speaking voices to run a fiefdom; the women providing the backbone through the pennies pinched from their domestic and teaching salaries; the church only opening its door and its beneficence to those who agreed. It seemed that the potential power of what has been dubbed "the most segregated hour in America, 11 a.m. Sunday," was scattered in too many directions, limited in its priorities, choosing choir gowns over housing, producing too few leaders who could take that clout into the white community and not compromise.

First Baptist Church, one of the oldest churches in the city, represents the typical ways of middle-class black Washington, a loyal, conservative congregation, its members part of the solid face of the city that survives the waves of political change and moves cautiously into the vanguard of social or political action. Here are a few of the voices of its congregation.

Eleanor Younger slid into her pew at First Baptist Church; her muscles, elastic from her daily joggin, were beginning to tighten from tension; the jaw of her round, compassionate face was tight. She had just lost her cool and yelled at a young Sunday-school teacher. As an office worker, widow and mother of two sons, Younger had learned to plan every minute. "She just seemed so slow leading those children up the stairs, Lord. So I just yelled, 'Miss so-and-so, get them up here quick, now.' It didn't dawn on me, Lord, that I had hurt her. But a few minutes later, the deaconess told me she was boo-hooing in the corridor. Please give me more patience and sympathy with others' ways."

First Baptist has stuggled to keep up with the changes outside its plain wooden doors and appears to have earned its support as a harbor in time of need. That role as a sanctuary will probably increase, as the country closes its civil-rights eye. Frank Tucker, the pastor, has his eye on another threat, the growth of the fundamentalist, predominately white organizations that broadcast their religious and political beliefs as one. "The growth of what is called the Moral Majority will certainly intensify the work of the black church in the 1980s. It will require a clearer definition of function, role and position," says Tucker, sitting in his modest study. The morning sunlight strokes his beige-and-brown-plaid, three-piece suit with a harvest glow. "It's going to require a sharpening of the educational process. If we are not careful, that conservative mood will win a lot of people away."

Sunday continues. The announcements about the Thanksgiving baskets, the essay and oratorical contest and the blood bank are over. The pipe organ, overcame by an unexpected hour of warmth and the shellacking of the pews, has sputtered its last note for the morning. "Looking but not seeing" is the minister's message, taken from two verses of Matthew. "People can look at a single event and interpret it in different ways," announces Tucker, looking over his glasses for some affirmation. Lips are still where the hand-fanned images of King, Kennedy and the Good Shepherd are moving. "Certain groups of Christian preachers have molded their views and made it palatable to groups of people. It has moved this nation backwards to a point of conservatism. They take the same edict you believe in and support their positions . . . like the superiority of one race over the other." Now Tucker is responding to the rustlings, the sighs of those who keep hearing the old questions, the old troubles. His black-and-red ministerial robes create their own stir of discontent.

"Do you have any idea of the significance of the murders in Atlanta, what's happening in Buffalo, what, a few weeks ago, the burning of a cross in our community means?" asks Tucker. Heads, the elderly with hat and curl, the younger bare and brushed back, are nodding. Here Tucker takes the message from close to home to closer to the soul. God hasn't changed says Tucker, though some individuals' interpretations might. "We need to look and see, we need to look and see," he implores, the softness of his voice gliding into a mannered shout. "Because some of us are looking and not seeing the power of God in our own lives."

"Preach, Reverend Tucker." The affirmation comes from the front row of the senior choir, from the rolling soprano of Sister Fannie Martin.

Sometimes, when the organ starts playing "Pass Me Not O Gentle Savior" during the morning meditation, Helen Tate cries. Tears of relief. She used to hold back her emotions during prayer, she used to have trouble praying. Praying just the way she wanted. Once she addressed the congregation about this dilemma, talked to the minister and didn't find the right connection until she was at another church one New Year's Eve. Now she prays just fine. She thanks God that praying during the meditation now is just like picking up the phone and finding someone you know on the other end. The Elder

One Sunday in 1910 Nellie Moxley topped her favorite blue outfit with a lace hat. Then she walked the four blocks from her family home to the frame building at 6th and G Streets SW and was baptized by Rev. W. J. Robinson. "When I joined, the church was in poor condition. You could sit inside and see the stars. There were two pot-belly stoves by the pulpit. The choir was in the back," says Nellie Moxley, now a 70-year-old invalid in a nursing home. Her life, outside the routine of three decades of a government job, has mirrored the panorama of the First Baptist Church. She has been superintendent of the Sunday school for 20 years, worked as the church clerk for 43 years, was a member of the senior choir for 36 years, outlived three pastors and now has the unofficial role of church elder. On Sundays the church bus picks her up and the short, heavy-set woman takes her precise, determined strides right to the front pew. With her the usher is a shadow, not a support.

Born in Deanwood, Moxley grew up hearing the first-hand accounts of a Washington now in the history books. Her father, Joshua Swann, had been a slave in Charles County, Md., and told stories about the hunt for John Wilkes Booth. Now Moxley in her own link to a fading past. Moxley, the oldest of five children, went to local public schools, then graduated from Minor Normal School. For four years she was a substitute teacher, but then she joined the U.S. Bureau of Engraving. In the 30 years before she retired in 1948, she worked herself up from a first printer's assistant to an examiner, from $1.25 an hour to $2 an hour. Just as her work in the external world was dictated by the laws and customs of the time, her own personal life was shaped by a strict code. When she talks of people she admires, she speaks of "their refinement, their devotion to their duties." She chuckles over her own memory. "I never stayed out of my mother's house a night until I was married. In those days they put a bell under the bed to know what you were doing. It was a Christian home, we never smoked nor drank," she says.

Her church work offered opportunities that the larger society put out of reach. As a member of the Baptist convention, Moxley went by train to California, Chicago, Memphis and St. Louis. "It was very nice in some places. I remember the streetcars in Memphis, where the black men had to get up and give the white women their seats. One of our ministers wouldn't do it and he had to get off," she says, her full, bronzed face giving no hint of her emotions.

First Baptist had few occasions without her presence. In 1934, the frame structure was replaced with a stone building. "We were excited. The new church meant our members were financially able to make the church last," says Moxley. Her memories are more of the ministers, the hymns, the day Marian Anderson came to sing, than any social upheaval. Rev. William Robinson, the minister when she joined, was "just like a father." G. H. Marshall, the minister from 1923 to 1935, was "polished." Rev. Lavelle Tucker, the minister who oversaw the church's relocation and 24 years of growth, was "almost like an angel."

Those years of shaping younger minds with a Sunday-school lesson give her an inner energy. Her favorite Sunday-school lesson was Ruth's Wise Choice. "And teach me not to depart; whither they goest, I go," she says, then gently says the words to her favorite hymns, "Jesus Savior, Pilot Me" and "The Lord Is My Light and Salvation."

Eleanor Younger's son was having trouble deciding whether to come home for the summer or attend summer school. Younger was fustrated that he was debating the issue in the long-distance calls from his college in Florida. wYounger, the superintendent of Sunday school, went to prayer meeting. "Please give me strength and guidance to do what's right. He's 20 years old now, all I can do is suggest." The next day, she recalls with the weariness gone from her voice, he announced his plans for summer school. The Activist

Helen Tate was attracted to First Baptist because she moved into the neighborhood, because her husband belonged and because she was restless. "I didn't do much at the other church. I would sit there and just wish to get out. But at first my mood changed. It was probably the civil-rights movement. I couldn't get involved because I couldn't leave my family, so I found an outlet in the church," explains Tate.

Since joining in 1962, she has been frustrated. Through her seven years as youth adviser, she has organized the mother and daughter teas, the weekend trips to Atlantic City, the bowling excursions, worked with the Cub Scouts -- but she has wanted more. There's a sign from her ample form, a sharp meeting of her eyebrows. "People are complacent. This is true of the First Baptist and everywhere," says Tate, who grew up on the Eastern Shore, used her high-school degree to work for the government for 30 years. She went back to college in 1970 and now works as a word processor at Riggs National Bank. "Rev. R. Lavelle Tucker sensed this. He was willing to do much more, but it wasn't on the congregation's agenda." She joined the March on Washington throngs in 1963, the other black solidarity days and now coordinates the city's Martin Luther King Jr. birthday celebrations.

In 1968 First Baptist opened its doors to the shelterless of the Poor People's campaign. "Since then I have seen people move from what is inside those walls to getting involved in the larger community," says Tate, who is chairman of the church's week-long anniversary programs. The church's outreach, she says, directly relates to the overall improved economic status of the members and the activism of the current pastor. "But people are getting side-tracked. It's the big end of the horn of plenty -- the two-or three-car garage, the detached home -- all that is over and above the need to be involved with the Lord on his day."

On the morning after she returned from a cruise, a vacation that was marred by hurricane-force winds and two days of sickness for Virginia Fleet, she was in church thanking God for her safe return. On the boat Younger, the president of the usher's board, who even takes Dramamine when fishing, had thought about how the Lord had calmed the seas. She wanted a repeat performance. And that Sunday morning, as she prayed, she made an agreement that that was her third and last cruise. The Deacon and His Daughter

On New Year's Eve in 1948, Ralph Peters took a homesick walk around his new Southwest neighborhood, looking for a church like the one back in Asheville, N.C. "I could hear the singing. Then inside, I felt a warmth, a fellowship, a level of understanding. And after the service everyone spoke to me," recalls Peters.

The church has become intertwined with his life. Ralph Peters is now chairman of the deacon board, worked with a group of other deacons to perform many of the church's duties when the First Baptist was without a minister. His daughter, Patricia Gagley, is church clerk, and his son-in-law is a deacon, and his grandson, a steady member. Yet, despite this inseparable association, Peters has never thought of abandoning bricklaying for the ministry. "I had an opportunity to see the struggle of ministers. The work of the ministry is not of your own choosing. You are guided by the spirit. And many times you are alone. Being a young person, I didn't want the struggle," says Peters, a tall, thin man, dressed in a flashy combination of greens.

The church, however, did provide that status of leadership and identity that outside work wouldn't give a black man in the late '40s and '50s. "When I first came here, the Italian I worked for set me up in a basement by myself. Then he let me hire another guy until I built up a team. But the blacks always did the basements. Out of one hole, in the next hole. In a way it didn't bother me. I needed the job," says Peters, 55, now a vice president of a masonry company. At the church, he was part of a decision-making group. "The minister would say, 'You can do it. No job is too big to do, if you put God first.'"

His daughter, Patricia Bagley, 33, has lived with the personal impact of his involvement. Her first commitment was enacted through daily morning devotions, reading of the Bible, nighttime prayers and the attitude of her parents toward their lives. "When a problem occurred, almost always we were asked, 'Have you prayed?' My parents always have had a sense of patience, peace and tolerance," she says. When one of her brothers was having problems at college, he would call home and pray. As a teen-ager, her life became inseparable from the church, from winning an oratorical contest to working as the junior church clerk. When she was a senior in high school, she met her husband at a wedding at the church. Last year he coached the church's basketball team, she coached the cheerleaders. And earlier this year, their oldest child, a 9-year-old boy, surprised them by walking up and joining the church one Sunday. "We don't go through many of the rituals. But I am not ashamed to say God has been good," says Bagley, a speech pathologist in Prince Georges County.

She has been curious about other religions. "Part of my satisfication is that I have been programmed, part of it is that I like the order of our worship. It doesn't seem quite right if a Sunday comes and we don't go to First Baptist."

Two Sundays after his home was almost destroyed in a fire, Reginald Hartman was sitting in church. He thanked God that no one was home at the time of the fire, thanked God for the generosity of the members who had collected for clothes for his family and asked God not to let him blame anyone for the fire. He thought about Job, how everything had been taken from him, but in the end he was better off. The Minister

When Frank Tucker was a freshman at Howard University, the stars from Blackstone, Va., still in his eyes, the dreams of a legal and business career still clear ahead, he went to his uncle's church one Sunday. "I was minding my own business, I didn't have any particular problems, things were going well," says Reverend Tucker. "I was not involved in the sermon, but with the sunshine and the stained glass windows. But God kept interrupting. Several times I tried to jerk away from the encounter. Only when I acknowledged that God wanted me to preach was there peace."

That very morning he faced the congregation and told them of his decision. But he was still looking for a compromise, a career that would combine the ministry and teaching. He tried it for a year in Florida. Four years ago he became the pastor of First Baptist. After praying, "Things seemed to be going so well for me in Philadelphia. I had been there 10 years. My question of God was what did he want me to do," says Tucker, 41, a man who feels uncomfortable with discussing his private voices. "There is a simplicity about faith, it's an ongoing type of thing. My outpouring to the congregation is not viewed by me as a glamorous opportunity. It's an awesome experience because you know people come to hear, to hear 'thus sayest the Lord.' You pray to shore up your limitations. And only history verifies the rightness of those personal petitions."

His questions have long receded. "I enjoy the sense of being in harmony with His will. The ministry itself is still just as burdensome. It's lonely at times and your only consolation is your harmony," says Tucker. Tucker has two degrees from Howard, sociology and divinity, and has worked with Shiloh Baptist and Takoma Park Baptist, as well as his decade in Philadelphia. He and his wife, a homemaker, have a teen-age daughter at McKinley High School.

In the last four years First Baptist has increased its membership to an active 1,200 with 600 at the two Sunday services, and opened the old mansion across from the church as a senior center, the focus of outreach programs that have a $40,000 annual budget. It has also started a summer day camp that enrolled 60 children, a day-care facility that reaches 90 children a day and a bus ministry that serves 250 on Sundays. "I think what we are doing is a 20th-century approach to Christ's 1st-century teachings."

Like most black churches, First Baptist has kept up a tradition of responding to the political plight of its members, through colonization, to the anti-slavery movement, to depression and segregation. Like many others, First Baptist has been pulled into the role of elective politics and contemporary issues like gambling. Tucker was against the recent gambling initiative that passed. That share his worry with the conservative mood. "But that wouldn't change my pulpit, as much as my political programs," he says.

But his pulpit is responding. A recent Sunday: "We think we are all right, we think we are doing fine, because there are no tragedies, no hardships," says Tucker, eyeing his congregation's shoulder-to-shoulder unity this morning. "But when you cut yourselves," and he gives the gospel yell of a long whoop, "you cut yourselves off from God. You pay the price."