"Keep Christ in Your Christmas."

The familiar slogan is marching across TV screens in the Washington area this year -- courtesy of the D.C. Baptist Convention -- as a reminder that beyond the tinsel and the parties and the presents, Christmas is a religious festival marking the birth of Christ.

Area churches have found a variety of ways to help their members celebrate Christ's birth by remembering, as He did, the poor, the lonely and the dispossessed.

Assumption Roman Catholic Parish in Anacostia distributed 500 bags of groceries to needy families in the area yesterday, and in the last couple of weeks, between 3,000 and 4,000 toys to parents anxious to make Christmas brighter for their children. Five hundred bags of groceries were distributed by the church at Thanksgiving.

According to the Rev. Thomas P. Kelly, pastor of the church, nearly 50 Catholic parishes and church schools in the suburbs and more affluent parts of the city collected the material.

The food and toys go "to anybody in the neighborhood who is in need," Kelly said. How do Kelly and his staff know if people are really in need? "We take them basically at their word," he said. "If you start to play detective, ask a lot of questions, you abort the message of what Christmas is all about."

Kelly, who declines to describe the community as poor -- "it's stable, and there's a lot of pride here" -- said area need for the church's program is growing.

A number of churches will serve Christmas dinner tomorrow to those who might otherwise go without. About 1,000 are expected at the Shrine of the Immaculate Conception, where Archbishop James A. Hickey will greet each guest, and 80 volunteers will serve the turkey and all the trimmings.

William Grillo of the Shrine staff, organizer of the annual event, said he had no trouble getting Christmas dinner volunteers. Some helpers "are individuals who don't have their families here," while others bring their whole family to help: "It sort of tops off their Christmas by being able to do that," he said.

Farther downtown, New York Avenue Presbyterian Church will provide its eighth annual turkey dinner for 250 senior citizens, 60 patients from St. Elizabeths and 40 former mental patients living in the community.

In addition, the Rev. Jack McClendon said, "We'll send home 300 doggie bags" with the guests.

Not all the church dinners are in areas of obvious need. St. Alban's Episcopal Church, for example, in the shadow of the Washington Cathedral in predominantly affluent Northwest, is preparing to feed about 100 persons tomorrow.

"Some of the needs are more emotional than financial -- there are people who would otherwise be spending the day alone," said Susan Curtis, who is in charge of the St. Alban's dinner.

Many churches encourage their members to expand the spirit of Christmas gift-giving. At Capitol Hill Presbyterian Church, as in many other congregations, members bought and gift-wrapped presents for patients at St. Elizabeths. "We had a good response" to that appeal, said the Rev. Donald Allen.

Allen said that he was aware of "a lot of members in his congregation reaching out to people who are alone and inviting them to share Christmas. That happens in most churches."

At the Church of St. Stephen and the Incarnation, church members are involved year around in a wide variety of programs to help the needy. In a recent newsletter the church pleaded its own case, publishing a list of items needed by the church, which readers were encouraged to add to their gift lists.

The list included everything from a filmstrip projector to rock salt for clearing icy sidewalks, to new doors for the dining room to incense and candles for the altar.

Southern Baptist churches nationally use the Advent season to gather money for their world mission program. At Vienna's Providence Baptist Church, the youth group set up a post office in the church vestibule. Church members were invited to drop off Christmas cards intended for others in the congregation and contribute to the youth group's mission fund the money that would otherwise have gone to the U.S. Postal Service.

Mt. Vernon Unitarian Church marked Christmas by raising funds for the NAACP by selling the Freedom Seals published by the civil rights organization.

Westmoreland Congregational, which, like many churches, has a number of social action projects going throughout the year, encouraged church members to bring children's mittens and hung them on the tree for distribution to needy children. Project chairman Sally Smith said it was chosen because people of all ages could participate.

Sometimes the spirit of Christmas sharing takes an unexpected turn. Throughout the winter months, volunteers at Luther Place Memorial Church operate a residence and a day shelter for homeless women. All year long, the pastor, the Rev. John Steinbrook, also is active in Jewish concerns.

On Christmas, the Luther Place people will take the day off. Their places at the shelter will be taken by Rabbi Lazlo Berkowitz and members of his Temple Rodef Shalom of Falls Church.