For 12 hours yesterday a stream of witnesses, from psychiatrists to teen-agers, from politicians to militant activists, lectured a panel of church leaders here on problems of city life and what the church should do about them.

The unusual day-long hearing, conducted in a stark, basement room of the downtown church of the Epiphany, was part of a developing national program for the Episcopal church.

The ultimate objective of the program is to identify major problems besetting the nation's cities and then to devise ways in which the church can attack these problems.

More than 25 witnesses appeared at yesterday's hearing to discuss a range of problems, including unemployment, crime and penal reform, hunger, abortion, housing, youth, the aging and death.

None of the witnesses questioned the appropriateness of church involvement in such issues. Most indicated the church should do more in these areas but do it more wisely.

"In the late '50s and '60s the church went out into the streets and emphasized the moral dimensions of our problems," recalled Sterling Tucker, chairman of the District City Council, in a reference to widespread church support of civil rights efforts.

Commending such activities, he continued: "Only when Sunday and Monday came together did people realize there was a connection between Sunday and the rest of the week."

Without such efforts by religious forces to apply Sunday preachments to daily problems, he said, "Sunday served an opiate to make what happens the rest of the week all right."

He challenged the churches to assume a new leadership role for today. "What the church has got to be about is to institute change. . . changing the way institutions serve people."

He cited as particularly serious problems in Washington unemployment, shortage of housing and the decline of neighborhoods.

Tucker also called for "efforts to recruit the kinds of industries (to Washington) that can provide jobs for the unemployed." Calling Washington a "company town" he said "We have the mentality of a company town, we assume that the company, like God will take care of us."

Witnesses at yesterday's hearing came from all walks of life, many church backgrounds and various areas of expertise.

Lloyd B. Addington, a demographer for the Defense Department used flip charts to illustrate population trends in the Washington metropolitan area. An active Episcopal layman, he pointed out that the church faces problems growing out of the changing life style which has brought with it a decline in the number of families to which, he said, "The Episcopal Church is traditionally oriented."

He cited a 42 percent increase in divorce over the last decade in Maryland suburbs; 26 percent increase in northern Virginia and 22 percent in the District.

Overall, he continued, "Fifty-seven percent of D.C. adults are single" adding: "The Episcopal Church has difficulty reaching this segment of the population." He noted that "the church is good at solving personal and family problems, but before the church can have any impact, people must first come through its door.The traditionally family-oriented Episcopal Church does not attract those who have the greatest need of and who can benefit most. . . he said.

The Rev. Milton F. Gay, Jr., an Episcopal priest who is also an urban planner in the Department of Human Resource's Office of Planning and Evaluation, told the panel that serious behavior problems among poor black urban youths stem from the youngsters' lack of self-esteem.

He said that the main sources of help for such youngsters lie "in the social institutions of religion, education and government: the social institution which has the most potential for impacting their lives, I submit, is religion."

In their testimony, other witnesses:

Pleaded for increased facilities and programs for outpatients and former patients of mental hospitals "who need a place in this world to belong . . . and something to do with their time."

Urged the churches to find and maintain emergency shelters for battered wives and battered children and elderly persons who have lost their homes;

Called for more clinics or other low-cost medical services "with fee on a sliding scale," which would be open evenings and weekends for persons with limited income.

Asked for alternatives to the present system of criminal justice, which witnesses said is both "inhuman" and has a high recidivist rate;

Urged support for establishing a hospice for terminally ill patients after the pattern of hospices in England.

The problems laid before the panel will be collated with results of similar hearings already held in Newark, Chicago, Seattle, Birmingham, Ala. and Colon, Panama, explained the Right Rev. John T. Walker, bishop of Washington and chairman of the National Urban Bishops Task Force which has organized the program.

"We hope that out of all this will come the beginnings of an urban mission for the church," he said.