On the morning of Jan. 4, John McAward was at home in Boston packing his bags for a trip later in the day to El Salvador. His phone rang. It was a friend calling from El Salvador: Two Americans and a Salvadoran were gunned down in a hotel dining room the night before.

It says something about McAward, who is the international programs director of the Unitarian Universalist Service Committee, that when the call ended he went on with his packing. He rejected all thoughts of canceling the trip, even though these were the fifth and sixth Americans recently to have been slain in El Salvador. The week before, an American journalist disappeared.

As it turned out, no harm came to McAward. This particular trip -- of 10 days -- was one of a dozen he has made to El Salvador and other Central American countries since 1977. Although McAward has been a close witness to the evolving violence in El Salvador, he and the UUSC have been providing one extraordinarily useful service here at home: helping to educate Congress to the political nuances of Central America.

That was the reason for the Jan. 4 journey. The committee had invited 40 members of Congress who were known to have foreign policy interests in Central America. McAward was making the advance arrangements for the three who accepted: Robert Edgar (D.-Pa.), Barbara Milkulski (D.-Md.) and Gerry Studds (D.Mass.).

Each was familiar with the work of the UUSC and its reputation for humanitarian service. Each knew that McAward could be trusted to arrange meetings with as many knowledgeable Central Americans as possible, from far left to far right. Any other way would be useless. The purpose in going was to eliminate preconceived notions, not get encrusted with more.

For 10 days, the group listened and learned. Although El Salvador was canceled from the itinerary -- for safety reasons -- the group met with Salvadorans who came to Costa Rica. The group also went to Nicaragua and Honduras. One of the differences in this trip, according to Edgar, was that it had little of "the grand tour treatment" traditionally given by the State Department to visiting bigwigs. McAward said, "All I asked of the delegation was that it include some talking to the victim class. Its side of the story was almost unknown in Congress."

On returning to Washington, Edgar, Mikulski and Studds began the slow educative work of snuffing out the myths, biases and ignorance about El Salvador -- its people, history, culture and politics -- that prevailed in Congress. From what was learned in Central America, the three presented evidence to support several conclusions: The Duarte government, which is not centrist, has little meaningful popular support and cannot control the military; most of the violence comes from the right; U.S. military aid can only increase the killing and terror; an American policy of getting tough with Cuba and the Soviets is a boon to Communist propagandists.

None of the three expected that these findings would turn Congress around. It would be enough if some opposition could be raised against the Reagan-Haig strategy that was then being sprung on both El Salvador and public consciousness.

Merely to begin the process of finding answers to the questions they returned home with would be a success: Why are we supporting the weak Duarte and arming the right? Why are we not consulting with governments like Mexico to develop a foreign policy rather than dictating one? What happens if a U.S. military adviser is killed? What are we offering in direct help to feed and educate the poor of El Salvador?

One measurement of the group's success is that when legislation to prevent U.S. military aid to the Salvadoran government was introduced in late January, 35 House members backed it. The number is now 73. That's a small number, except that some years ago when the House first voted on a similar bill on getting militarily involved with a corrupt and weak government, it passed with almost no opposition. That was Vietnam.

If a few politicians know better this time, it is due in part to the productive and crucial work of John McAward and the UUSC. Creating a climate of understanding is an emphatically unsplashy process that wins no headlines. But it does open minds, and no humane policy in Central America can be formed without that.