Pope John Paul II used the religious high point of his pilgrimage to Poland today to make a solemn plea for the promotion of human rights, national freedom and the sovereignty of states.

Up to a million people gathered beneath the walls of the 14th century monastery of Jasna Gora to hear the pope remind the Communist rulers of Eastern Europe that states are truly independent only when they serve "the good of society." Millions more heard the pope's words on state television and radio in one of the few live nationwide broadcasts of the eight-day trip.

The pope was speaking at an open-air mass to close celebrations marking the 600th anniversary of the arrival in Poland of the country's most revered religious image, the Black Madonna of Czestochowa. By taking part in the festivities, which were extended by six months in his honor, John Paul was keeping a promise that he made in June 1979 on his first trip to his homeland since becoming pope.

Later, presiding over a special meeting of the Polish episcopate, the pope called on Polish bishops to continue "to speak the truth." He expressed full support for church demands for the release of political prisoners, the reinstatement of workers dismissed from their jobs, and the restoration of independent trade unions.

The pope already has demonstrated his willingness on his present trip to speak out on sensitive political and moral issues and make clear his support for the ideals of the banned Solidarity trade union. It is therefore significant that today, during the most important engagement of his pilgrimage, he chose to address what for a country within the Soviet Bloc is the most delicate theme of all: the meaning of words such as freedom and national sovereignty.

Speaking in a strong, clear voice, the pope said that a nation is only "truly free when it can shape itself as a community determined by unity of culture, language and history." He added: "The state is firmly sovereign when it governs society and allows the nation to realize its own subjectivity, its own identity."

At this point a wave of gathering applause swept across the crowd, which extended back from the wide meadows beneath the monastery down the main street of this grimy industrial town. But the pope, in perhaps his only concession to his Communist hosts, cut the ovation short by asking people to listen in a spirit of silence and religious reflection.

"The sovereignty of the state," the pope went on, "is deeply linked to its capacity to promote the freedom of the nation and develop conditions that commit the nation to express all of its distinctive historical and cultural identity."

In Warsaw, Poland's Communist authorities issued a statement warning that official promises to lift martial law fully and return Poland to normality could be "adversely affected" by political demonstrations at masses. The statement was issued following the chanting of antigovernment slogans in Warsaw and Czestochowa and the appearance of Solidarity banners in the vast crowds.

The statement, read by government spokesman Jerzy Urban at a press conference, said the authorities viewed these events with "seriousness, fearing that they might bear on relations between church and state."

The statement suggested that the church had not kept its promise to prevent "hostile manifestations" during and after the religious ceremonies and called for respect for "the jointly adopted arrangement" for the remainder of the visit.

As on previous days, there was a scattering of political banners in the crowd today, including one that read, "Lead us in love toward independence," and was signed by the outlawed nationalist group, Confederation for an Independent Poland. There were also numerous names of Polish towns written in the familiar Solidarity logo with a Polish flag sprouting from one of the letters.

Half the people in the vast assembly could not even glimpse the pope because of the thick woods that surround the monastery, situated on a hill above Czestochowa. The ceremony was relayed to them by loudspeakers attached to trees and lampposts as they huddled beneath umbrellas in the cold wind and steady drizzle.

Only a fortunate half million or so pilgrims who had been assigned special places in the meadow could see the pope. Next to the pontiff were the serried ranks of the Polish bishops, in their resplendent golden robes, who make up the leadership of the most vigorous Roman Catholic church in Eastern Europe, if not the world.

Behind them, on the battlements of the fortified monastery, were the eagles that have formed the emblems of the independent Polish nation since its conversion to Christianity in 966.

Recalling past invasions by foreign powers, the pope said that the monastery of Jasna Gora was identified with the hopes of the Polish nation for recovering its independence. And he quoted from the words of a favorite hymn: "Before your altars we entreat you, oh Lord, deign to restore to us a free homeland."

He went on: "It is here, too, that we have learned the fundamental truth about the freedom of the nation: the nation perishes if it deforms its spirit--the nation grows when its spirit is ever more purified and no external path is able to destroy it."

The pope said that Poland's "very difficult geopolitical situation" and "painful history" had sharpened the sensitivity of Poles to fundamental human rights such as "the right to freedom, to sovereignty, to freedom of conscience and religion, and the right to human work."

In his address to the Polish episcopate, the pope said he was convinced that "the true aspirations of the workers" were "fully met by the social doctrine of the church."

"The Christian doctrine of work postulates both the solidarity of workers among themselves and the need for honest solidarity with workers," he said, evoking the name of the communist world's first independent trade union, which was legally disbanded in October 1982, after the imposition of martial law in December 1981.

This remark was in direct contradiction to the official Marxist doctrine in Eastern Europe, which states that religion is "false consciousness" and that only the Communist Party truly expresses the "objective interests" of the workers.

The Vatican spokesman, the Rev. Romeo Panciroli, said that the long-awaited meeting between the pope and Solidarity leader Lech Walesa would not take place in Czestochowa as expected. The most likely place for the encounter now seems to be the southern city of Krakow, where the pope has a day free of official engagements before he returns to Rome on Thursday.

After opposing the meeting between the two men, the government finally agreed that it should be allowed to take place following personal appeals by the pope to Poland's military leader, Gen. Wojciech Jaruzelski, and after the pope agreed to attend a formal reception by the Polish government, which Jaruzelski had sought.