In anticipation of Congress' vote next Wednesday on President Reagan's $36.2 million contra aid package, religious leaders on both sides of the issue have stepped up efforts to convince legislators of the rightness of their views.

Through lobbying of individual legislators, news conferences, self-styled hearings and demonstrations, a variety of activists are trying to drive their point home.

On Thursday, the Roman Catholic social justice lobby, Network, brought to the Capitol leaders of a dozen religious orders of people who evaluated the situation through the experiences of their missionaries on the scene in Nicaragua. They were unanimous in their efforts to persuade Congress to reject any further aid to the contras.

Maryknollers, Jesuits, Dominicans, Franciscans and others rehearsed their arguments at a news conference in the Cannon Office Building before meeting with legislators and their aides.

"We firmly believe that a vote for any contra aid on Feb. 3 is a vote for war and against the peace process," said Sister Nancy Sylvester, national coordinator of Network, in introducing the panel of religious leaders to the media. Even so-called humanitarian aid to the contras, she said, "is fueling a war. We have chosen military might instead of the peace process."

"The Maryknoll Sisters have been in Nicaragua since 1944; we are neither neophytes nor naive; and we cannot keep silent while the U.S.A. pursues a course of violence, injustice and immorality," said Sister Luise Ahrens, president of the order.

Like many who spoke, Ahrens expressed outrage over the course of recent U.S. foreign policy in the region. "In 1979, a country of about 3 million people . . . overthrew a cruel dictatorship," she said.

"The U.S. was silent about democracy in Nicaragua in the Somoza {dictatorship} days and was silent after the revolution until the new government began to implement social reforms -- a national vaccination program, increase of literacy from 12 percent to 55 percent, clinics in every rural province with doctors and medicine."

With the U.S. church leaders was the Rev. Ignacio Urbino, a Nicaraguan priest who was injured when the Jeep in which he was riding struck a land mine. "I don't come to defend any ideology or any system of government," he said through an interpreter. "I come only to speak as a pastor of poor peasants . . . to speak of their situation in war."

Urbino said that as of last July 3, the date of them children -- had died as the result of the war.

"All this is the fruit of dollars sent from the United States to Nicaragua."

The Catholic leaders repeatedly cited the of his accident, 43,000 Nicaraguans -- 2,000 support of both U.S. and Nicaraguan bishops in calling for negotiations rather than continued military action to bring the conflict to an end.

Sister Miriam Theresa Larkin of the Sisters of St. Joseph of Carondelet said both the government and people of Nicaragua have begun to implement the Central America peace accords.

Displaced people are being returned to their homes; commissions for peace and reconciliation have been established throughout the countryside and have begun work on amnesty programs; La Prensa newspaper and the Catholic radio station have been allowed to reopen, and the exiled Bishop Pablo Antonio Vega has been allowed to return, she said.

But she was reminded that only the day before, Vega had appeared on Capitol Hill talking about human rights violations of the Sandinistas.

"No one is claiming the Sandinista government is morally pure," said Aherns of Maryknoll.

Sister Sheila McGinnis, superior of the Philadelphia-based Medical Mission Sisters, compared the situation on Nicaragua to Vietnam, where she said she worked for eight years. "I have the impression of having been there before," she said.

Beyond actual physical devastation, she said, "It is the war with the contras, backed and supported by the U.S. government, that is increasing the {Nicaraguan} defense budget and decreasing the monies for food, health services and any other human services for the general population of that country."

She reported "a tremendous increase in serious malnutrition in children," as a result of Nicaragua's war-inflated economy. "It takes 2 1/2 days to earn enough money to buy one cabbage."

Rep. Mary Rose Oakar (D-Ohio) told the Network news conference that when the House Democratic Caucus, of which she is vice chairman, meets on Tuesday, she will work "to solidify our consensus against any aid" to the contras.

President Reagan has asked Congress to vote $36.2 million in lethal and nonlethal aid to the contras, of which 10 percent for military assistance would be held in escrow. If the Sandinista government fails to reach a cease-fire agreement by March 31, the military aid would then be released, according to the Reagan proposal.

But the Catholic leaders here this week refused to differentiate between lethal and nonlethal aid.

"President Reagan can turn the truth around to fit his ends, but giving aid to the contras now, as it has been in the past, is giving aid for war and not for peace, said Sister Barbara Karl of Notre Dame de Namur.

Any additional aid to the contras should come "after the cease-fire has been declared . . . to help them reestablish their lives, not to fight anymore," she said.