Three minutes before the House chaplain's prayer for "love and forgiveness" opened the lame-duck session of the 96the Congress yesterday, Rep. Robert E. Bauman was in his usual place at the minority table.

As is customary at an opening session, members of the club that is the House of Representatives put aside their political differences long enough to exchange greetings. Among the first to shake hands with Bauman was Minority Leader John Rhodes from Arizona. Then came Demorcrat Claude Pepper of Florida.

Since the last time he was in the chamber, Bauman's personal life as well as his political career had come unraveled, and so, like mourners greeting the bereaved at a funeral. Bauman's colleagues didn't linger, moving on after offering condolences, but not spending too much time near the corpse.

As the afternoon wore on, the Maryland Republican often found himself sitting alone, a tragic figure brought down from a lofty position of respect because voters in his Eastern Shore district were unable to square his pronouncements about the sanctity of family life and old-fashioned virtues with his admission that he had succumbed to the "twin compulsions" of alcoholism and homosexual tendencies.

Bauman, the founder of Young Americans for Freedom, the president of the American Conservative Union and an outspoken conservative leader of the House for the last seven years, was one of only three Republican incumbents in the House rejected by the voters last week. Just at the moment in history that his uncompromising conservative philosophy was going to be shared in the White House and at the opposite side of the Capitol by a Republican-controlled Senate, he will be back in Easton, searching for a new livelihood.

In the last month of his unsuccessful campaign, he had promised voters that it would be "the new Bob Bauman" who represented them in Congress, and it was this model of subduedness, for the most part, who appeared on the House floor yesterday.

During the 15-minute break for the first quorum call of the session, one not initiated by Bauman for a change, he chatted with reporters in the ornate Speaker's Lobby. In keeping with his pledge to give priority to his long-neglected family, Bauman boasted that he already has ordered "a 25-pound turkey for Thanksgiving dinner at home" and has purchased tickets for a performance of "The Nutcracker" ballet, which he will attend "whether or not the House is in session when the curtain goes up."

Bauman, who came to the House at age 15 and has spent more than half his 43 years working there, was his usual dapper self yesterday in a dark blue three-piece suit, with striped shirt, dotted tie and white handkerchief. He acknowledged that he had lost some weight during the ordeal, but said his physician had pronounced him "in perfect health" after an examination Tuesday. p

And the man who liked to explain that his constant presence was needed on the floor because "every minute Congress is in session, America is in danger" found time yesterday for a 90-minute lunch break.

Bauman said colleagues from "right, center and left" had told him they were "very sorry" about his defeat, but he said he told them he had learned that "nobody's indispensable."

While he contended that yesterday "wasn't any different than any other day," a tinge of bitterness slipped into his otherwise good-natured banter with reporters.

When asked how he planned to support himself in the future, he smirked, "There are a lot of questions I don't have to answer anymore, and that's one of them."

Bauman's first appearance at the microphone also marked a departure. Yes, he was being critical, but rather than liberals and Democrats, his targets were "certain friends in the conservative movement" who were questioning the conservative credentials of President-elect Ronald Reagan. Reagan had "worked too long to have his integrity questioned," Bauman said, and predicted that by early next year, the new president "will be at the top of enough liberal hit lists to satisfy" all conservatives.

Later in the day, Bauman reverted to form. While chatting in the back of the room with Illinois Rep. Bob Michel, a likely successor to Rhodes as minority leader, Budget Committee Chairman Robert N. Giaimo (D-Conn.) sought to get unanimous consent to move ahead of a budget resolution.

Bauman bounded from his chair, sprinted down the aisle and blurted out a phrase that has been his trademark: "Mr. Speaker, reserving the right to object, the gentleman from Maryland. . ."