PANAMA CITY, Panama (AP) _ A Roman Catholic priest told worshipers on Sunday not to be intimidated by riot police who the day before had crushed a violent demonstration against Gen. Manuel Antonio Noreiga.

Hundreds of people gave standing ovations and cheered repeatedly during the homily by the Rev. Javier Villanueva.

''There is no suffering, no blow from a truncheon or a stream of poisonous water, nor an insult, nor criticism, nor pain that does not form part of the suffering of Christ,'' he told about 500 people at Christ the King Church.

On Saturday, police trucks equipped with water cannons fired a mixture of tear gas and water at about 400 demonstrators, most of whom were members of an opposition women's group, during a march on the north side of Panama City.

Riot police also fired tear gas cannisters and birdshot to scatter the protesters, who threw rocks and blocked streets with flaming barricades of tires and trash.

Noriega, chief of Panama's 15,000-member Defense Forces and the country's strongman, is under indictment by a grand jury in federal courts in Florida on charges of drug trafficking and money laundering.

The Reagan administration has imposed economic sanctions on Panama, including freezing Panamanian assets in the United States, in an effort to oust Noriega. The measures have caused an acute cash shortage in Panama that has helped spur anti-Noriega protests.

Jose Manuel Faundes, a lawyer for the independent Human Rights Commission, said six people were arrested during the three-hour demonstration Saturday. No one was reported injured.

The rally, which followed a church service, was organized by the Union of Civic Women.

Before Sunday's Mass began, a young man handed out photocopies of a cartoon published last week in the pro-government newspaper La Republica. The cartoon depicted Catholic Archbishop Marcos G. McGrath on a cloud and as a Nazi.

''Get off that cloud and come here to reality,'' said the caption.

The man said he was a member of the National Civic Crusade, a coalition of 200 political parties, business, labor and student groups formed last June to try force Noriega out.

But people waiting for the Mass grabbed stacks of the cartoons, tore them up and threw them away. They also screamed, ''Toad,'' a term used in Panama for people who spy on the opposition for the Defense Forces.

Some Latin American leaders asked McGrath last month to mediate the conflict, but several days later the archbishop said his efforts had failed and he blamed Noriega's ''intransigence.'' Since then the pro-government news media has repeatedly denounced McGrath.

In his homily, Villanueva said the use of propaganda ''is the tactic of Marxist-Leninist Communism'' and Catholics should not let ''communists and degenerates'' create divisions in the church.

''We are willing to suffer ... the suffering of solidarity, of unity. We are going to pull our own national resurrection that we need,'' the priest said.

The economic sanctions have created a severe economic crisis in Panama. Banks, schools and most government offices remain closed.

The campaign to remove Noriega intensified on Feb. 26, when he ousted Eric Arturo Delvalle from the presidency after Delvalle tried to fire the general the day before.