Faithful followers of the Islamic faith must respect the beliefs of other religions, an Islamic scholar and the Pakistani ambassador to the United States said during an unusual interfaith service at the Washington Cathedral last Sunday.

"The Koran teaches that God has sent his revelation to all peoples from time to time and that no section of mankind has been left without divine guidance," said Ambassador Sahabzada Yakub-Khan.

"Indeed the Koran requires belief in the truth and righteousness of all the prophets and in the revelations that were vouchsafed to them," he said. "The Torah and the revelations that came to Jesus are repeatedly mentioned as sources of guidances and light."

Islam, he continued, "seeks to bring about reconciliation among the followers of different faiths and to establish a basis of respect and honor among men . . . all of them are invited to united on the basic principles which they all profess."

The ambassador was the main speaker in an interfaith service for world peace and justice, sponsored by the Council on Religion and International Affairs.

Participants included leaders from Roman Catholic, Protestant, Jewish, Buddhist and Islamic traditions.

Ambassador Yakub-Khan, who gave the main address, quoted extensively from the Koran to demonstrate the primacy of tolerance, mercy, brotherhood, justice and peace in the Islamic tradition.

"The true brotherhood of mankind which Islam envisages can be brought about by virtue of man's relationship through God," he said.

While the Koran "takes note of diversities of race, color and language," he said, "neither membership of a particular tribe nor citizenship of a particular state confers any privileges nor are these factors a source of honor," he said.

The Koran, he continued, also contains "numerous specific injunctions for the pursuit of peace and against the creation of disorder . . ."

In the Islamic faith, he said, "Mercy is indeed among the foremost divine attributes; Muslims initiate every act, in the name of 'the most merciful.'"

On brotherhood, he said, the Koran is most specific when it asserts that Muslims "'believe in Allah and that which is revealed unto us and that which was revealed unto Abraham, and Ishmael, and Isaac, and Jacob, and the tribes, and that which Moses and Jesus received and that which the prophets received from their Lord.'"

The worship service was held in conjunction with a meeting here of the board of the Council on Religion and International Affairs, an independent and nonsectarian organization concerned with relating ethical and moral concerns to international affairs.