Mother Teresa of Calcutta passed through Georgetown University graduation yesterday almost as quickly and spectacularly as angels of God have been said to appear before people on Earth.

Her entrance and exit were mysterious, her stay brief and shielded, all of which added a tinge of excitement to her presence. She appeared on the stage, a tiny figure with hunched shoulders wearing a frumpy gray sweater over her starched white habit, dwarfed by the standing ovation of university deans and officials resplendent in their black academic robes and caps.

Under an expanse of gray sky, the 1979 Nobel Peace Prize winner exhorted the assembled graduates to "become carriers of God's love."

The 9,000 graduates, family and friends rose to their feet on the lawn outside the Healy Building of the Georgetown campus when the university president conferred an honorary Doctor of Humane Letters degree upon Mother Teresa Bojaxhiu, the 71-year-old Catholic nun who has devoted her life to helping the poor of India. In the words of the degree citation, "She has so vividly renewed the love of Jesus Christ for the wretched of the earth whom our political and economic structures have pushed aside."

She was accompanied by three gentle-looking Catholic nuns, all in habits identical to hers. Mother Teresa had another graduation to attend at Niagara University in Niagara Falls, N.Y., at 2:30 p.m. ("We asked her first," said Father Charles McNamara of Niagara University) so Georgetown moved its ceremony to 11 a.m. instead of 2 p.m. Because she didn't have much time, Georgetown had conferred the other honorary degrees the night before. "Well, it was getting kind of long," said one public- relations official of past graduations, "and Mother Teresa's on a tight schedule." Vice-provost Marie-Helene Gibney denied that Mother Teresa was the reason for this year's change.

However, her schedule is tight. Today, she'll be back in Washington to receive an award from the Knights of Malta in Anacostia in the afternoon and one from the Fordham University Club of Washington in the evening. On June 9, she'll be Class Day Speaker at Harvard University in Boston.

She had arrived in time for the baccalaureate mass earlier in the morning, then went to the office of Georgetown's president, the Rev. Timothy S. Healy, where she chatted with university officials. "She told us that every morning they feed 7,000 people in Calcutta," said Father J. Donald Freeze, the Georgetown provost. "They spend all night preparing the food."

Mother Teresa smiled during the conferring of degrees at the euphoria that swept graduates into rowdy whoops, hollers and applause as each school of degree candidates was asked to stand. There were 1,449 graduates yesterday, 625 of them from the College of Arts and Sciences. Healy had some fun with his task: "I hereby confer upon you the degree of bachelor of science in business administration," he told business school graduates, "with fear and trepidation for the future of the nation." And to the nursing school graduates: "Mother Teresa is accepting volunteers directly after the ceremony."

After receiving her degree, Mother Teresa said, "I am most unworthy of this great honor, but I accept it for the glory of God and in the name of and for the glory of our poor people around the world . . .

"God loves us," she told the graduates in a steady, strong voice. "We are precious to Him. He knows us by our names. He has carved us in His hand . . .

"What you have received is not for you only," said the Yugoslavian-born woman who spent 20 years teaching in India before becoming an Indian citizen and working with the poor. "The less you have, the more you can give. The more you have, the less you can give. You have received much, but especially you have learned to pray, for the fruit of prayer is faith and the fruit of faith is love and the fruit of love is service . . . Jesus said, 'Love as I have loved.' "

Young people, she said, "are hungry for God. Deep down in your hearts you have hunger for God . . . do not be afraid of Him . . .

"Suffering, humiliation, joy, success, sorrow--it is all part of life. 'And if you want to follow me, you must take up the cross,' God says."

She spoke of love: "If a young man loves a young woman, this is beautiful. This is how God wants it. But love each other with a clean heart. Give to each other a virgin heart, a virgin body."

And she noted, "The family that prays together stays together." The audience chuckled softly. "This is my prayer for you."

As she neared the end of her speech, big splotches of rain suddenly fell from the sky. "Let us thank God for His love and let us thank Him for the rain," she said, smiling, and left the podium. The president quickly concluded the ceremony.

Immediately Mother Teresa and her three colleagues were whisked from the platform, accompanied by several university officials and flanked by uniformed security men. They were ushered past the lawn to a side entrance of the Healy Building, up a flight of stairs and down a long corridor to a doorway onto the quad area behind Dahlgren Chapel. It was an exit worthy of any rock star.

Mother Teresa, followed by the three nuns, walked outside into the courtyard while men holding umbrellas high over the nuns' heads trotted alongside in the rain. The doors to a long, gray limousine were opened briskly and they stepped inside. The whole trip from speaker's platform to car took maybe three minutes. The limousine drove them to a waiting private plane (at an undisclosed airport) provided by a member of the Georgetown University board of directors who prefers to remain anonymous, according to Father Freeze.

Outside, the rain was ending and graduates congregated, talking with friends and taking pictures of each other. "I thought what she said was appropriate," said graduate Maria Oliva, 21. "It's nice to hear someone speak about the spiritual side of life."

"I thought it was excellent," said another, who asked not to be identified, "but as a Jewish student I couldn't relate very well to going out to work for the Lord Jesus." He shrugged. "But you could find something to relate to in her speech."

Her remarks about virgins did not go unnoticed. "Has she found any virgins here?" cracked one student. "People around me were trying hard not to laugh. But I don't know how she meant it. If she meant it literally, she's out of touch."

"There were a few snickers in the crowd," Suzanne McAfee said. "But I didn't laugh. When it comes from her, it's sincere."