The Unitarian Church in Sacramento is a long way from the turmoil in South Africa. It is a modern, airy structure of wood and glass set in an affluent residential neighborhood. Outside, the street is so green with lush lawns and trees that their color dominates.

Inside, Rep. Robert T. Matsui (D-Calif.) was trying to bring South Africa home, telling some 200 of his constituents, "Many people say that South Africa is not our concern, that it's an internal matter . . . ." But, he said, "We live in one world. And we have a responsibility to others, irrespective of borders."

The audience was mostly religious and peace activists, a group that Matsui might have expected to be fully receptive on South Africa -- more receptive, at least, than others he had seen this recess as he tried to sell the idea of tax reform and a not-too-distant tax increase to some fairly resistant, and in some cases hostile, listeners.

Most of those who gathered in the church were more interested in promoting a nuclear freeze, and opposing U.S. involvement in Central America, than in South Africa.

Matsui urged, "There are two reasons we have a responsibility in South Africa. One is moral . . . . Americans are defaulting on our moral responsibilities. People no longer believe that we will, in fact, do right."

The second reason to intervene in the fight over apartheid, Matsui said, is "strategic. If we wash our hands and say we're not going to be involved, there will be a revolution." And with that revolution, "it could be another area where the Soviet Union makes inroads."

One woman told Matsui she was from the Netherlands, and had heard that blacks in South Africa don't want American intervention: "If those people are going to be hurt, shouldn't it probably be their decision? Did they ask you for those sanctions?" Another asked, "How do you respond when someone says sanctions and divestiture would hurt more than help?"

Matsui gave his answers: "Unless something drastic is done, the status quo will continue." Reaching back more than two decades to the memories of the American civil rights movement, Matsui said that the Rev. Martin Luther King Jr. could have stayed home, and Rosa Parks could have continued to sit in the back of the bus. "But once in a while, people have to sacrifice."

Some in the audience were friendly to the idea of intervention in Africa. Mark Carlson, a lobbyist for the Lutheran church, wore a bright yellow T-shirt that urged: "Free Namibia!" And some had concerns closer to home. One man wanted to know, "Is a change in leadership going to make things better?" Matsui laughed: "I'm not going to say anything bad about 'Tip' O'Neill."