An amendment authorizing prayer in public schools will pass this session of Congress, Sen. Jesse Helms (R-N.C.) told a cheering rally of school prayer advocates this week.

"I think before this session is over, we are going to have legislation that you folks will like," Helms told a Monday gathering of about 100 persons assembled under the National School Prayer Breakfast Coalition Committee umbrella.

Speakers at the breakfast, at the Key Bridge Marriott, drew on the Korean airliner tragedy to buttress their arguments for school prayer.

Helms, just returned from a conference in Korea marking the 30th anniversary of the U.S.-Korean Defense Treaty, recounted with considerable emotion his encounter, during a stopover in Anchorage, with one family on the doomed flight. He had listened to the mother read Bible stories to her two small daughters.

Helms said he mourned their deaths, "but I know where they are. But what about the little ones who have never been exposed to prayer? When I think of that I think about the absurdity of those who say the First Amendment prohibits prayer."

Philip A. Guarino of the Republican National Committee, was introduced by prayer breakfast coordinator, Mary Elizabeth Bull, as "a confirmed Catholic Christian" who was "ordained at the Vatican." Guarino also drew on the airliner tragedy and the death of Rep. Larry McDonald (D-Ga.) who was taking the plane to the defense treaty meeting. "As we listen to the voice of one man, his lips are saying as he goes down: 'Heavenly Father, we want you back in our schools,' " Guarino said.

Vonette Bright, wife of Campus Crusade director Bill Bright, called the Supreme Court ruling outlawing religious exercises in public schools "an insult to God, to whom this nation was dedicated by our forebearers. Because of the Supreme Court rule, there are 40 million young people being denied the knowledge of God."

Bright said that such problems as "venereal disease, abortion, alcoholism, teen-age pregnancies, delinquency and drugs . . . are directly traceable to the removal of prayer from the public schools."

Two religious leaders whose names appeared on promotional material for the breakfast both disavowed involvement with the coalition. Archbishop James A. Hickey of Washington and Rabbi Harold White of Temple Sinai and Georgetown University said they had made it clear that they would not participate in the pro-school prayer rally.

"I told Mrs. Bull that I was not into that at all," White said.