A "marriage of pastor and people" is taking place at the largest Baptist church in Washington, a church that, despite a 112-year history, is having some trouble adjusting to new leadership after having flourished under the guidance of the same pastor for 43 years.

"Metropolitan (Baptist Church) has been a forceful, dynamic, telling church due to its leadership," said one Baptist minister here who has known the church and its work for 33 years.

The Rev. Dr. E. C. Smith, 80, is being replaced by the Rev. Dr. H. Beecher Hicks, Jr., 34, an outspoken man with a history of intense political and civic involvement that featured the Rev. Jesse Jackson, head of People United to Save Humanity. The landmark Metropolitan church is at 1225 R St. NW.

Membership has declined slightly since Dr. Smith's retirement last Jan. 31. But Dr. James Cheek, president of Howard University expressed his support for the church by becoming a member since.

"We have picked up 60 new members since Dr. Hicks joined us in early September," said Mrs. H. A. McNair, a church official.

Though the frail health of Dr. Smith during the latter years appears to have had some effect on the dynamism that had marked the church, the majority of the congregation has continued its sometimes flamboyant expressions of love and appreciation for him. He was named pastor emeritus for life, including a pension, which is not always done in smaller churches.

President of the NAACP in Pittsburgh in 1973, Dr. Hicks then moved on to Houston where he was on the board and vice president of the Houston branch of the Urban League.

Happy to be in Washington partly because "it's the flagship fo the world," Dr. Hicks said his political activities would be limited to those that would "have some bearing on the life and the life style of the members whom I'm committed to serve here at Metropolitan."

Part of the recognition Metropolitan has achieved came from Dr. Smith's long years of struggle within civil rights groups. His old friend, the Rev. Dr. Andrew Fowler of Capital View Baptist Church on Capitol Hill, cannot recall a single major civil rights activity that Dr. Smith was not a part of.

"Three of four other preachers have come to Washington with prior experience in civic and community activities, and couldn't overcome the vastness of Washington's bureaucracy," he said. "However, it appears to me that Rev. Hicks is going to be a definite asset in these areas."

Dr. Fowler is executive secretary of the Committee of 100, an interdenomination group of ministers who regularly make their views known to the District Building. Dr. Smith, until last year, was its chairman for 30 years.

"The first meeting after I arrived, I became a member of the Committee of 100," Dr. Hicks said. Committee membership is now over 400, according to Mr. Fowler.

Dr. Hicks, who has written a book about American black preachers published this year by Judson Press, talked of their roles - with Dr. Smith at his side - in the church lounge last Wednesday.

"I think that the civil rights movement brought into focus the place of the church in the lives of black Americans. That importance was there before the civil rights movement began, and it is still there today. Whether or not the larger population (whites) is able to conceive or able to appreciate that importance is a question for debate. But I think the importance of the church all over this country, in terms of the black community is . . . stronger than it has ever been."

Dr. Smith agreed saying, "There was a time when the church gave itself largely to worship, but knowing that people who worship were part of the whole political weaving, the church began to spread and become more interested in community problems."

Metropolitan, he said, has shown a membership decline, as have many city churches, since the 1950s. He attributes it to such changes within the community as:

A neighborhood population shift.

Former residents of Southwest Washington, displaced by urban renewal of the 1950s, moving into the neighborhood as more affluent residents moved out.

Parking problems. He estimated that more than 10.000 people worship within a radius of a few blocks each Sunday.

Increases in crime in the area.

Dr. Hicks estimates the congregation includes 3,000 people though the mainsanctuary seats only 1,400. "There are always standees," he said. He already has installed three closed circuit television sets in the lower auditorium to seat 300 more. Since 1938, Metropolitan's sersvices have been transmitted through a nonenergized telephone line to Stoddard Baptist Home, two miles away at 17th and Newton Streets NW.

Whatever the degree of diversity among the membership of his large congregation, Dr. Hicks' former pastorates offer experience in dealing with them.

"I had a downtown upper-class black congregation in Houston . . . Mount Ararat (Baptist CHurch) in Pittsburgh was similar to Metropolitan. It was an urban, inner-city congregation in the heart of what I thought was one of the most unusual settings. It was in the midst of a black-Jewish-Italian ghetto."

There is one facet of his work in the past that, in their words, has troubled some members of the congregation - Dr. Hicks' work with a planned parenthood group.

"I did a great deal of work with Planned Parenthood in Pittsburgh," he said. "I did it at a time when the whole question of abortion was just beginning to blossom in America."

His role, he said, was to help women examine the options presented to them, not to take a "judgmental view as to whether a person ought to have an abortion or ought not to have an abortion . . . I did not do that counseling as a minister, I did that counseling as a practitioner of the counseling art."

One church member said many others "would have a fit at the mention of the word abortion."

But for those who would worry about "controversial" aspects of Dr. Hicks' work over the years, there are an equal number who recall times when Dr. Smith verged on difficulty with some elements of his congregation.

But, as it turned out, Dr. Smith now is seen by many as "the best administrator of any church in the United States," said Mr. Fowler. "Everything at Metropolitan is all set to go. It is greased, tuned, set up, like a car at the top of a hill, all ready to roll."