"What we really aspire for is peace," said the soft-spoken Nicaraguan pastor. "We would like to see the Reagan administration put its trust in negotiations that the Contadora nations are espousing."

That was the message Gustavo Parajon, a Harvard-trained physician who is also pastor of the First Baptist Church in Managua, peddled on Capitol Hill earlier this week, lobbying against the Reagan-backed package of military and humanitarian aid to the contras.

In addition to heading a church, Parajon is the founder and president of CEPAD, the Spanish acronym for an umbrella organization of Nicaraguan Evangelicals, as Protestants in Latin America are known, involved in direct relief and development aid.

In an interview, Parajon was questioned about charges by Catholic leaders that the Sandinista regime has curtailed religious freedom.

"We have not experienced in the Evangelical church the same problems of the Catholic hierarchy," Parajon said. "We are able in the Evangelical churches to carry out our work."

He acknowledged "some problems in areas that have a lot of war activity," but added that "when authorities have been abusive . . . when we have talked to the government, we have had explanations; we have had our grievances redressed."

In 1982, he said, when local groups took over some buildings belonging to the Seventh-day Adventists, "we protested to the government and the properties were by and large turned back."

Last fall, he said, when three pastors were jailed, one for 11 days, "We interceded with the government and they were released."

Parajon said one of the men, the Rev. Boanerger Mendoza, was later questioned about his experiences by an official of the U.S. Embassy. Subsequently, Parajon continued, the Voice of America broadcast "reports of people being tortured, held naked in refrigerated rooms."

When Parajon queried Mendoza about the reports, "He said it was not true."

But there are limitations on churches, he said in response to a question. At the Evangelical radio station, which is on the air 18 hours a day, there are "guidelines" for broadcasters "not to talk about political events." The same guidelines were in effect, he said, under the Somoza regime.

About 85 percent of Nicaraguans are Catholic, Parajon said, and the rest Evangelical. "Most of the Jewish people left after Somoza." He denied charges, leveled by some Jewish groups in this country, that Nicaraguan Jews were driven out by anti-Semitism of the Sandinistas. "That has been confirmed not to be true," he said.

CEPAD, which represents 18 Nicaraguan church groups, has "dialogue with the government every month where we can talk about our problems," he said. "We act as a body of church people coming together to talk about the life and mission of the church in a revolutionary society." CEPAD is helping resettle some 30,000 displaced persons uprooted by the continuing warfare in border areas.

Parajon did his undergraduate work at Denison University in Ohio and earned his medical degree at Western Reserve, then went to Harvard for a degree in public health.

He started the cooperative CEPAD after the devastating 1972 earthquake, initially to try to coordinate relief efforts. CEPAD's current annual budget of $400,000 comes from Church World Service, the Mennonite Central Committe, the Christian Reformed Church, Lutheran World Relief and church groups in Western Europe.

" . . . Thousands of Americans have come to Nicaragua in the last several years" to see for themselves what conditions there are. "We always encourage that," he said.