Mayor Walter E. Washington went to the Men's Day celebration at Tried Stone Fire Baptized Holiness Church of God in the Americas the other Sunday to tell worshipers: "March not only to the church and to the pew, but to the polls."

City Council Chairman Sterling Tucker, in his campaign to unseat the mayor, took his family to Choir Day services at Shiloh Baptist Church recently. They heard the minister, who is chairman of a group of clergymen supporting Tucker, preach to the congregation about the Bible's teachings on the need for change.

Marion Barry spent the early afternoon hours of last Sunday mingling with the crowd in the Founder's Retreat, a downstairs dining hall at Metropolitan Baptist Church, where the Bailey Memorial Tithing Club was serving dinners of chicken and green beans.

Other cities have their block clubs and precinct captains, their ward heelers and political bosses. In Washington, it is the church - for decades the cornerstone of black community life - that has emerged as a major political battleground in campaigns for elective office.

"The only organized political strength in this city is the church and particularly the Baptist church. There ain't no Democratic Party here. They can't get you elected," said one leading city Democrat twice elected to public office and involved in the election of others as well.

"If you want help, you go to the churches," he said. "If they close their doors on you, you can pack up your bags."

Less than two months remain in the Campaign of Washington, Barry, Tucker and others for the Democratic nomination for mayor in the Sept. 12 Democratic primary election. That primary is expected to be close, and the role of ministers has become a key one, because the churchmen are regarded by many as the city's homegrown politicians and native-son power brokers.

They wield influence in a key segment of the city population. They can be counted on to deliver three of the most precious political commodities - workers, votes and occasionally money.

"They are probably the most tested leadership of any group in the city," Tucker said. "Sunday after Sunday they have to face their congregations, who accept them and respect them as leaders."

The Rev. Lola Johnson Singletary, the daughter of an influential Baptist minister, said that in many instances pastors can be assumed to be speaking for at least 51 percent of their followers.

"It's the nature of the animal. They all deliver the congregations because of the fellowship. You've got to maintain that much prestige or you can't remain the minister in a Baptist church," said Singletary, who managed Hilda Mason's successful campaign for city council last year.

For years, the black church has been a center of community life, providing a forum for the exchange of ideas. It buried the indigent, fed the hungry and was a refuge for the down and out long before there was a D.C. Department of Human Resources.

It was perhaps the most stable institution in this city's disenfranchised black community, where local government was subject to the roller coaster whims of politicians from every part of nation except the District of Columbia.

Even after home rule, the church has continued to play a prominent role in the lives of thousands of residents in this overwhelmingly black city.

At Shiloh, for example, a 114-year-old institution at 1500 9th St. NW. there is some type of church activity nearly every night of the week, ranging from prayer meetings and Bible study classes to nutrition and tennis clubs and visits to musical shows at the Kennedy Center.

The 5,000-member congregation in intricately organized in dozens of committees, boards and church circles. It has annual budget of $675,000.

The upward mobility of blacks in the city government during the past two decades has enchanced the ability of Shiloh and other churches like it to care for its community.

The head of Shiloh's housing task force, for example, is Monteria Ivey, associate director of the D.C. Department of Housing and Community Development. Joseph A. Beavers, a church trustee, is vice president of the influential Greater Washington Central Labor Council. Beavers, who acts as the church's ombudsman, has direct access to Mayor Walter E. Washington on church problems.

"When there were no politics, there was the church. That's been the backbone of black life," said William Lucy, former chairman of the D.C. Democratic State Committee.

Once the city acquired limited self-determiniation, the church, which had vigorously agitated for civil rights and home rule, became a major attraction for candidates, many of whom covert its support more than that of any other institution in the city.

Among the things that draw political hopefuls to the church is the belief that these weekly captive audiences, usually of several hundred people each, are made up primarily of people who vote.

"You get the 'good solid citizen' kind of people in church," said Tucker. "You get moderate income people, or some of them are poor. But there's a sense of religious and civic responsibility. They go hand in hand."

Joe Carter, a principal strategist for the Barry campaign organization, said. These people are heavy voters. People that go to church are really hardcore voting people. These people can make a difference in the election."

A poll taken in June by The Washington Post supports this contention. Of 1,020 registered Democrats questioned, nearly three out of four said they attend church services often and were "almost certain" they would vote in the crucial Sept. 12 primary.

Of those responding, 33 percent said they are Baptist, 19 percent Catholic and 12 percent Methodist. Blacks, who made up 71 percent of the respondents, made up disproportionately large segments of these religious groups, accounting for 98 percent of the Baptists, 73 percent of the Catholics and 85 percent of the Methodists.

Beyond the voting strength of its members, the church is important politically because it gives candidates access to a complex and effective informal network and a pool of well-connected campaign volunteers.

"You've got an awful lot of people in the church who are older, who are not working, who have a lot of time on their hands and know people," Lucy said. "They've people who everybody trusts and everybody believes in. If they've superactive , there's a network that goes all across the board - usher boards, choirs and the like. Something like that just doesn't exist outside the church."

When the Washington campaign wanted people to circulate candidacy petitions, it found some of the weekly meetings of the Baptist Ministers Conference of Washington, D.C.

When a campaign worker for mayoral candidate Dorothy Maultsby wanted signatures on some of her petitions, he found about 40 in a single unit at a Metropolitan Baptist Church choir rehearsal.

When John Ray, a political unknown, needed workers for his campaign for mayor, he turned to the Rev. Hosea Browne of the John F. Kennedy League for Universal Justice and Goodwill, a ministers' group. League members got volunteers for Ray from among their influential church members.

Some candidates also value church endorsements as a form of character witness. "It's an indication that the person is of leadership stature and responsible behavior," said Tucker."It's a testimony of the faith and character of the individual, the character of their personal life and the character of their leadership."

The Rev. Andrew J. Allen, pastor of First Baptist Church of Deanwood, for example, once publicly asked that Mayor Washington be blessed "not because we think he is the best man in the world, but because we do not want to see him succeeded by the worst man in the world." Allen would not elaborate on this comment.

Church leaders have used their Sunday radio broadcasts or weekly church newsletters to boost the candidacies of politicians. In some instances, city political observers recall, church-owned buses have been used to take voters to the polls on election day.

Washington has the strongest support among churchmen. It is built on his 20 years as an unofficial legal adviser to the Lott Carey Baptist Foreign Missionary Convention as well as on his marriage to Bennetta Bullock, daughter of the late Rev. George O. Bullock, a prominent Baptist minister.

The Baptist Ministers Conference, which represents about 300 Baptist clergymen, and the Committee of 100 Ministers, an interdenominational group, have endorsed Washington. The mayor believes that the church, labor and senior citizens are the three major components of his political base.

Tucker, who campaigned with Washington in 1974, has skimmed off some of the mayor's former church supporters, including, Bishop Smallwood E. Williams of Bible Way Church, who is highly regarded in political circles, and the Rev. E. C. Smith, pastor emeritus of Metropolitan Baptist Church.

Tucker concedes the support of most Baptist church leaders to Washington, but thinks he can pick up votes from rank-and-file Baptist church-goers.

The major contest for church support is between Washington and Tucker. However, Barry, too, has been going to church regularly, hoping to gain some support, and will soon announce formation of his own group of ministerial backers, according to Barry strategist Joe Carter.

The Barry campaign is not counting on getting a large share of the church vote. What it does hope, however, is that Washington and Tucker will split the bulk of the votes from this important constituency, thereby decreasing the chance that either will beat Barry on the strength of an overwhelming church vote.

City political observers disagree on the extent to which the endorsement of a minister influences his congregation. In more fundamentalist groups, such as Pentecostal denominations and some Baptist churches, a large majority of the congregation will follow the pastor's lead, it is believed.

But in other congregations, where members are more affluent, better educated and politically more sophisticated, observers say, a smaller portion of the congregation will support the minister's choice. In some churches, ministers even feel it is out of place to become openly involved in partisan politics.

"There's a kind of popular notion that you don't talk about religion and politics.

"There's a kind of popular notion that But the gospel is supposed to deal with the total man," said one minister who is politically active, the Rev. Henry C. Gregory III, pastor of Shiloh, who heads the group of churchmen supporting Tucker.

"But to the degree that we see the need for addressing issues we will certainly corelate the gospel with the issues," Gregory said when he announced his endorsement of Tucker in May. "Love without power is mere sentiment."