Inside Shiloh Baptist Church yesterday, the mourners found comfort in thier tears. Having lost faith in the police, the FBI and the horde of descended investigators, they came 2,000 strong seeking justice, as one preacher put it, from "He who presides over the Supreme Court of the Universe."

Words from men of the Lord, dressed in their velveteen robes and draped with red and black mourning ribbons, were their only consolation on this day, one filled with the sorrow of reports that still another child - number 22 - is missing in Atlanta. Is there no end to this vigil of tragedy which has spawned fears even in distant Washington that racism knows no bounds?

Hand fans cooled their faces, hankies dabbed their eyes, music lifted their voices and one child solemnly lit a candle for the two Atlanta children still missing.

"I feel so helpless -- so alone," said Mrs. J. P. Blair, fist tightly clenched in her lap, head raised to the ceiling. She is the wife of a Baptist minister, the mother of four children. "I think there is something racial going on. And it doesn't stop in Atlanta. I really think there are people out there who hate blacks and they believe they can destroy us if they can kill our young males. God, i hate to say it but that is my honest feeling."

A few seats away, Metcalfe C. King, vice president of a company named Balmaya Investment, clasped his hands, hung his head and let the organ music bring a glaze of tears to his eyes.

"Just a prayer for those whose hearts are heavy," the hefty man said softly. "It doesn't make no difference whose doing it. The fact that it is being done is cousing me distress. That's why I'm here."

The memorial service of prayer and justice, as it was called, was not just for the missing and slain children of Atlanta -- but for slain blacks in cities across the country. Sponsored by the Council of Churches of Greater Washington, the ceremony was not advertised in any of the city's major media, but the grapevine of the black community sent out a distress signal that summoned forth a congregation rivaling a Sunday service.

The crowd streamed into the church during the noon hour, klatches of five to 15 people crowding the sidewalks as they made their way from work and home. One man even wore a blue jogging outfit.

Atlanta has struck a deep and bitter chord.

D.C. Mayor Marion Barry summed up the anxieties, bringing the congregation to its feet in a release of emotion.

"A certain mood exists in this country encouraged by the leadership, that it is all right to do anything to black people," Barry said. "Now I maintain that if those were 21 white people, we would have no problem (getting the federal government involved)."

The church exploded with applause.

Some of Washington's most influential ministers joined the mayor in accusing President Reagan of "neglect" in handling the the Atlanta investigation.

"Last Sunday, Reagan worshipped at the United Capital Union Presbytery," said Dr. Edward White, an elder at that church. "I'm not bragging, I'm confessing. If you had been there, you would have seen more secret service and police in church than worshippers. If we live in a land where the value of life is equal, I wonder if he would provide the children of Atlanta with the same pequal, I wonder if he would provide the children of Atlanta with the same protection he affords himself."

Altogether, 18 ministers, including the Rev. Walter E. Fauntroy, D.C. delegate to Congress, kept asking the same questions in different ways: dIs the killer so smart that he can't be caught? Is it really possible that no one has seen anything? Are the police incompetent? Couldn't the federal government do more?

"Now if the killers are all white," Bishop John Hurst Adams of the African Methodist Episcopal Church asid, "then the white community should be so supportive that we all understand that it was the internal chaos of the culprits, not their color, that is the issue. Now, perchance, if one of the killers is black. . ."

The crowd grumbled loudly.

"We need to understand that it's the person's inner chaos, not his color," Bishop Adams repeated.

Services at Shiloh were just one of several held yesterday. There was standing room only at the St. Matthew's Lenten services that not only marked the beginning of Lent, but also the Day of International Prayer requested by the Atlanta Committee to Stop Children's deaths.

"Twenty-one children murdered or missing in Atlanta. Fear, agony, helplessness and vulnerability -- surely we turn our prayers to Atlanta today -- to the parents, the city and to our sister church," Archbishop James A. Hickey told the congregation. "The tragedy of an American city, the tragedy of Atlanta, is but one -- very present and compelling -- but one instance of the violence which stains our country and our world."

On Monday, a March for Survial is scheduled to being at 10:30 a.m. from the justice Department and proceed to the steps of the National City Christian Church on Thomas Circle.

"This is the first gathering I've heard about in Washington and frankly I had no idea that so many people would come together like this," said Clara Toombs, special assistant to a U.S. congressman, who took her lunch break to attend the Shiloh service. "If we can work together, pool our resources -- our strength, our time, even money, I believe this will be solved."