Joseph P. Weinberg, 62, senior rabbi at Washington Hebrew Congregation, who had been active in interracial and civil rights efforts since the 1960s, died at his Potomac home Friday night after battling brain cancer for more than a year.

Rabbi Weinberg, who was known for his concern for social issues, had served for 31 years at Washington Hebrew, the city's oldest Jewish congregation and the largest Reform congregation in the Washington area. For many of its thousands of members as well as many others in the community at large, he was the human symbol of the congregation.

His death came a little more than a month after the rabbi delivered an emotional farewell sermon on Rosh Hashanah, the Jewish New Year and one of the holiest days in the Jewish calendar.

With the help of his three children, who each read portions of the sermon, Weinberg told a packed sanctuary he had just learned that he must "battle anew with my pesky invader" but wanted "to have Rosh Hashanah as usual."

He said the holiday was a reminder of "God's great gift to us . . . the precious gift of time," which is "ours to fill wisely, joyfully, completely." The ailing rabbi told his congregants to rejoice that "we are still here. Still alive, to stand for causes that are just . . . to bear witness to the majesty of the human soul. Still alive!"

The Sept. 11 sermon was the first time many in the congregation realized "what was really happening as far as his health was concerned," recalled Kenneth Marks, president of the Northwest Washington congregation. "The mood was quite emotional.

"Joe Weinberg and the congregation were one and the same, basically," Marks added. "What can you say when you lose someone who meant so much? This is the most compassionate man you ever met in your life. He always wanted to do good, and he always had time for you."

Weinberg's brain cancer was diagnosed in March 1998, and he underwent surgery twice, his wife, Marcia Weinberg, said yesterday. On Friday evening, the family had gathered for the traditional Shabbat prayers, and Weinberg, his wife recalled, "left us while the candles were still burning."

Since his arrival in Washington in 1968--a time when the city was wracked by racial riots and anti-war protests--Weinberg played a leading role in efforts to improve racial relations and fight poverty. He helped organize Ya'chad, a Jewish organization promoting affordable city housing, and Carrie Simon House, a transitional home for unmarried mothers in Northwest Washington, which is supported by Washington Hebrew.

Weinberg also was a moving force behind his congregation's annual service held jointly with local African American churches to honor the legacy of the Rev. Martin Luther King Jr. on the Jewish Sabbath right before King's national holiday.

Marcia Weinberg, 61, said her husband had been deeply affected by his experiences when he marched with King in the historic civil rights march in Selma, Ala., in 1965. Then a young rabbi, Weinberg was arrested twice.

"It was an important moment for him as a human being and as a rabbi," she said. "Joseph was very motivated by social action."

Weinberg was born in Chicago in 1937. His mother, Helen Joy Weinberg, was an artist, and his father, Alfred, a businessman. In 1938, as the Nazi menace was threatening European Jewry, Alfred Weinberg returned to his native Germany to bring his parents and several other family members to the United States.

After graduating from Northwestern University in 1958, Joseph Weinberg immediately entered seminary at Hebrew Union College-Jewish Institute of Religion in Cincinnati. After his ordination in 1963, he served as assistant rabbi at a San Francisco congregation before coming to Washington.

Weinberg, who also was a fervent supporter of Israel and campaigned for years to help Soviet Jews emigrate, became senior rabbi at Washington Hebrew in 1986. He was only the fifth rabbi to hold that position since the Reform congregation was founded in 1852.

The original congregants held services in their homes until they purchased a building site in the 800 block of Eighth Street NW in Chinatown. There, they built their first synagogue, which they sold 58 years later. Today, the former temple, which still has the Star of David in its stained-glass windows, is home to Greater New Hope Baptist Church.

Washington Hebrew, with a membership of more than 3,000 families, is now located on Macomb Street NW. Funeral services for Weinberg will be held at the congregation tomorrow at 1 p.m.

In addition to his wife, Weinberg is survived by a sister, Judith Adler, 66, of Seattle; a daughter, Rachel Weinberg of Arlington; two sons, Jonathan Weinberg of Potomac and Josh Weinberg of Bethesda; and four grandchildren.

CAPTION: Rabbi Weinberg spent 31 years leading Washington Hebrew.