President Reagan told a group of more than 100 religious leaders yesterday that his administration is maintaining its "fundamental commitment to the poor," but he called on churches and voluntary groups to accept more responsibility for the needy "rather than leaving it to the bureaucracy."

"The story of the Good Samaritan has always illustrated to me what God's challenge really is . . . ," the president said. "He didn't go running into town and look for a case worker to tell him that there was a fellow out there that needed help. He took it upon himself."

In a luncheon speech in the State Dining Room, with an audience including Moral Majority leader Jerry Falwell, Cardinal Terence Cooke and the heads of many of the major religious denominations in the country, Reagan talked of what he called the churches' traditional "catalyst" role in helping the poor, adding that he believes the field has been "co-opted by government."In his invocation, Cooke said there was a role both for the government and for churches and citizens to minister to those in need.

Reagan attempted again yesterday--as he has repeatedly in the past month--to counteract the view that his economic recovery program is designed to enrich the well-off at the expense of the poor.

"While we've quite justly, and out of economic necessity, cut some budgets," he said, "we have not, contrary to what seems to be the perception, abandoned America's commitment to the poor."

Some of the religious leaders were not persuaded.

"Obviously that was no news to us that the churches have been playing the catalyst role," said the Rev. Dr. Avery Post, president of the United Church of Christ. "The question that came to me was that he was not dealing responsibly with the catalyst role that government has to play."

Administration cuts in health, housing and employment programs and Reagan's call for charity and voluntary help to pick up some of the slack represent "more than a light shift in values," Post said. Those policies indicate, he said, "a shift back to a patronizing attitude toward the poor."

"We barely heard the word justice in those meetings," Post said, referring to meetings before the luncheon with members of the Presidential Task Force on Private Sector Initiatives.

"It was clear . . . that he identifies justice with charity, which is a concept we do not accept," said William P. Thompson, secretary of the General Assembly of the United Presbyterian Church. "We think the role of government is being reduced to the point where people will suffer more, try as the churches may to respond to their needs."

The president, in defending his economic recovery program against perceptions that it is unfair to the poor, said that overall government social spending is up in the fiscal 1983 budget he sent to Congress, and he noted proposed increases for Head Start, Social Security and Medicare. The programs that were cut, he said, were either "inefficient, top-heavy with bureaucracy" or did not come close to "accomplishing what they set out to do."

Reagan has proposed deep spending cuts in vocational education, food stamps, child nutrition, and programs for the handicapped. The president's budget would provide for no new subsidized housing starts and would end energy conservation programs.

Three television networks boycotted the president's address to the religious leaders to protest new rules on coverage of the president. ABC, CBS and Independent Network News refused to cover the speech because only one television correspondent was allowed into the State Dining Room, although cameras were permitted. After ABC and CBS each declined to be the sole television correspondent permitted in the room, NBC agreed to accept the position.

Senior White House officials have objected to reporters using picture-taking sessions to question Reagan and have promised that Reagan would have regular question-and-answer sessions with reporters instead.

After the luncheon, some of the guests gathered at St. John's Episcopal Church, where buttons were passed out. "The poor have suffered enough," they said.