The Ethiopian and Eritrean bishops conducting Mass in a Northwest Washington church yesterday did not know which of the children standing before them were descended from which of the two warring countries. Nor did they care.

Side by side, they blessed each youngster from the confirmation class of the Kidane-Mehret Ge'ez-Rite Catholic Church, hoping to send a message of peace to their governments and countrymen.

"You are going to be confirmed in the faith of your fathers and mothers, in the faith of your grandparents," Abune Berhaneyesus D. Souraphiel, archbishop of the Ethiopian Catholic Church, told them.

Their faith at times will be tested, "just as the faith of your parents today is being tested," Souraphiel warned. "When there is no peace . . . when there is suffering, when things are sad."

Most of the 20 or so children confirmed yesterday were born in this country to parents who emigrated from the Horn of Africa long before Eritrea gained independence from Ethiopia in 1993.

The neighboring countries--whose governments grew out of guerrilla movements that worked together to overthrow an Ethiopian ruler--enjoyed friendly relations for five years. Then, a border dispute over 160 square miles sparked a bitter, bloody conflict that has claimed thousands of lives and, in its 19th month, remains in a tense stalemate.

The war has fueled ethnic and tribal hatred in the two North African countries and soured some relationships in immigrant communities here. But the Roman Catholic Church has remained united and advocates steadfastly for peace.

Only about 1 percent to 2 percent of Ethiopians and Eritreans are Catholic. The rest of the population is Muslim, Eastern Orthodox or evangelical Christian. Leaders of all four religious groups in each country--including the two bishops--met in Oslo in September to sign a joint appeal for peace.

When members of the Kidane-Mehret learned that Souraphiel and Abune Zekarias Yohannes--bishop of Asmara, the Eritrean capital--would be traveling separately on business in the United States, they decided to invite them to jointly celebrate a "Mass for Peace."

Church members traded their small sanctuary near Catholic University in Northeast Washington for the larger pews of St. Gabriel's Catholic Church on Grant Circle. Turnout was about double the 150 to 200 people who usually come for Mass, said Abba Tesfamariam Baraki, the church's pastor.

Scripture was read in the Ethiopian language Amharic as well as in Tigrinya, the Eritrean language, and each bishop gave his homily in his country's tongue, with some English translation.

"We are praying for peace, and we are worshiping together," Baraki said. "The two countries are too much suffering, too much destruction."

Yesterday, Souraphiel praised the religious community for remaining unified. "I don't know of any other people who is at war, and who comes together and prays together," he said.

The Mass offered several reminders of the historic closeness of the countries. Yohannes, the Eritrean bishop, greeted an Ethiopian couple celebrating their 25th wedding anniversary. He officiated at their marriage as a parish priest in the Ethiopian capital a quarter-century ago.

Aklilu Zegeye, an Ethiopian economist living in Fairfax, said he had also known Yohannes in Addis Ababa and considered him "like a father."

"It is more or less the rulers that are doing all of this," Zegeye said about the armed conflict.

From the next pew, his niece, Marakinesh Kassaye, disagreed. She arrived from Ethiopia just a year ago, after the fighting started, to earn a master's degree at Howard University. Normally, she does not attend the Catholic church. But she came yesterday because the Ethiopian bishop is her mother's cousin.

"There is no unity at all," Kassaye said. "We're not together anymore. We're two different countries. We don't like each other."

Reluctantly, Zegeye let her have her say. Then he made his point again.

"We are just one," he insisted, gesturing at the full pews, the voices raised in prayer. "We are really headed along that direction."

CAPTION: Michael Sultan, a native Eritrean, leads a procession of Ethiopian and Eritrean Catholics at St. Gabriel's Catholic Church.

CAPTION: Ethiopian Archbishop Abune Berhaneyesus D. Souraphiel, left, and Eritrean Bishop Abune Zekarias Yohannes walk in the procession at St. Gabriel's.