The large red brick church is not grand, but it's a steadfast pillar of the Washington community. Its members may not be illustrious, but they faithfully cram its sanctuary Sunday after Sunday, and it is such a beehive of community activity that the doors rarely close.

The down-to-earth qualities were just what CBS-TV was looking for in its Easter telecast, and so, beginning at 10:30 a.m. Sunday, viewers of Washington's WDVM and all along the network nationwide will be swept into Shiloh Baptist Church at Ninth and P streets NW.

There they will be treated to a Sunday service of a proud and extraordinary church that has been working for several months to accommodate itself to the electronic age and still honor the Lord in fitting and proper fashion.

In the church's bows tothe CBS eye and its new celebrity, there will be four choirs, instead of two; a sermon cut from the normal 25 minutes to a rigorously monitored 20 minutes, and blessings, introductions and hymns timed down to the second.

The sign reminding people to tithe has been removed temporarily. The ceiling is newly repaired and there will be a special security staff and a souvenir program with booster ads.

There will be one collection instead of two, and air conditioning -- no matter how cool the weather -- to control the heat generated by the television lights. The paper fans with the funeral home advertisement, normally a must for stirring the still air, have been benched by church leaders who consider them "too distracting."

For a while it had appeared the children's and youth choirs were going to sing barefoot, but the shoes went back on when it became clear that the directional microphones would not pick up the little feet shuffling in and out of the choir loft.

But most of the accommodations have bee directed at meeting the strict requirements of a television offering that will last one hour, not one second more or less. And so eight subcommittees have worked feverishly for weeks to perfect each detail of the service.

Timing each segment is necessary because "we don't want to waste time on transitions and movement and then get cutt off in the middle of Rev. Gregory's sermon," said Mary Frances Spruce, the program coodinator who timed a recent rehearsal, one of two such full-scale preparations, in order to prevent such a mishap during the totally live program.

Spruce, stopwatch in hand, found the processional hymn was 42 seconds longer than allotted, the moment of meditation two minutes and 33 seconds too long and the children's and youth choirs 10 seconds overtime. On the other hand, the collection of tithes and offerings (to empty pews) and the invitation to prayer finished 81 seconds early.

Throughout all the excitement and welcome disruptions, Shiloh members and officials have been careful not to forsake the deep religious significance of the day. Easter, the celebration of the resurrection of Jesus Christ, is the most joyous of Christian holidays, one celebrated elaborately in most churches.

One who has clearly takenit all in stride and kept it in perspective is the pastor, the Rev. Henry C. Gregory III, an instructor at the Howard University Divinity School and renowned for his preaching style. "I don't have time to get involved in this, I have a church to run," said the fourth-generation minister. Sunday, he will speak on "Where Broken Lines Meet," because "I think there are lines of communication that are really broken down today -- in families, in the nation, in the world."

Gregory said he wasn't even particularly surprised when he was told of CBS' plans. "I almost live with a surprised look on my face since I've been at Shiloh for the past eight years," said Gregory.

Stage fright is a foreign emotion to Gregory, whose sermons are taped and broadcast each Sunday morning over the radio.

Gregory said he doesn't force any long-term effect as a result of the televised service, just that "it's an opportunity to extend the ministry we think is already important."

For Gregory, the last four weeks have also been a lesson in diplomacy. "We have nine singing organizations. How do you decide who's going to sing?" he said. But his 4,600-member congregation is very pleased, he said.

If the Shiloh Leadership has any regrets, it is that the church doors will have to be closed once the 800 capacity is reached. As on regular Sundays, as many as 250 in an overflow crowd will be able to watch the service on a closed-circuit television in the auditorium. But church officials doubt that that arrangement will be sufficient and anticipate turning many away.

Shiloh's choirs, of course, will have some of the best seats in the house as they present their gospel numbers, traditional anthems and Handel's "Hallelujah Chorus."

But they've been rehearsing more than hallelujahs during the past month, according to Charles Fleming, director of the 95-member senior choir. "We've been practicing standing and sitting in unison and our attacks and releases so we all begin together and close off together."

Despite the careful attention Shiloh members have given each detail of their big day, they've taken pains, they said, to assure that what viewers see Sunday will be as close as possible to the authentic Shiloh Baptist service that they have come to love.