Pope John Paul II arrived in Poland today to a welcome of profound yet dignified emotion from throngs of his countrymen and praise from the Communist leadership that hailed him as a "son of Poland" and a man of peace.

Kneeling to kiss the ground at Okecie Airport, riding slowly through the crowded streets of Warsaw in a raised carriage and conducting mass in Victory Square before about 250,000 people, the pope clearly was moved by what he portrayed as a personal pilgrimage.

Poland is "my native land," the pope said in his first remarks, "the roots of my light, of my heart, of my vocation."

Yet his words at events throughout the day also recognized the broader significance of his nine-day stay in a land where church and Communist authorities have abiding differences. He spoke openly on such sensitive themes as human rights, freedom of conscience and the church's ancient role in the state.

"Christ cannot be kept out of the history of man in any part of the globe," the pope said in his homily, at mass, touching off applause and chants from worshipers of "We want God," which resounded in the cavernous square.

Earlier, standing face-to-face with Communist Party leader Edward Gierek in a meeting at 18th century Belvedere Palace, the pope said the task of the church is "to make people more confident, more courageous, conscious of their rights and duties, socially responsible, creative and useful . . . "

"For this activity the church does not desire privileges but only and exclusively what is essential to the accomplishment of her mission," he said in a blunt reference to restrictions on church functions and expansion in Poland over the years. Ninety percent of Poland's 35 million people are Catholics.

Gierek, in remarks carefully chosen to balance Poland's communist ideaology with the intense nationalism of its Catholics and pride in the selection of a Polish pope, said the party is prepared for detente between church and state for the sake of Polish unity. Yet he also mentioned the primacy of Polish ties to the Soviet Union, where rigid atheism is the rule.

For all the excitement and anticipation here about this visit, the attitude in Warsaw today seemed at most time as much reverential as joyous.

Crowds numbering in the hundreds of thousands gathered at dawn to line the streets on the pontiff's eight-mile route from the airport. Some sang. Many placed flowers at the curbside. Nearly all were quiet and polite, despite the hours-long wait. As the papal caravan approached, people pressed forward with broad smiles.

The dramatic high point of the day - and surely one of the most striking scenes in modern Catholic history - came as the huge crowed prayed at the mass celebrated by the pope in Victory Square.

A late afternoon sun gave the setting a soft glow. Poles, those present and the countless numbers watching a live nationwide television broadcast, heard a Polish pope urge them in ringing terms to follow Christ. His words were made even more meaningful because of the strong mix between religion and national celebration.

Almost every passage in his sermon had deep significance to Poles, and some passages were controversial.

The pope began by recalling that Pope Paul VI had "ardently desired to set foot on the soil of Poland" but never had. Unspoken but known to all Poles is that Paul's request in 1966 was rejected by the Communist authorities.

Then the pope observed that this year is the 900th anniversary of the death of Saint Stanislaw, one of the leading Polish saints and a predecessor of John Paul as bishop of Krakow. This, too, was heavy with symbolism since Gierek and his colleagues, invovled in a complex dispute about the saintis proper role as a human right advocate in Polish history, postponed the pope's arrival so that it would not coincide directly with the Stanislaw celebrations.

John Paul II recalled for listeners that Poland had suffered in World War II and was "abandoned by the allied powers." Many Poles took this to be a particular criticism of the time Soviet troops stopped their advance short of Warsaw while Nazi occupation forces destroyed the city.

On a similar theme, as he stood not far from Poland's tomb of the unknown soldier, the pope declared, "There can be no just Europe without the independence of Poland marked on its map! On how many battlefields has that soldier given witness to the rights of man, indelibly inscribed in the inviolable rights of the people, by falling for our freedom and yours."

Here, too, there was prolonged applause.

The pope arrived in Warsaw at midmorning on an Alitalia jet and was greeted by the ceremonial Polish president, Henryk Jablonski, and the primate of the Polish church, Cardinal Stefan wyszynski. He stood for the Polish national anthem, reviewed an honor guard and generally was accorded the protocol of a visiting head of state.

Jablonski's brief speech stressed the "exceptional character of this solemn moment . . . our satisfaction is all the greater because the Polish nation will play host to its son, who after elevation to the highest church office, spoke the memorable words that he was with all his heart with beloved Poland, the motherland of all Poles."

After the triumphant processional through the streets of the Polish capital, the pope went to the city's cathedral in a section that had been almost totally destroyed during the war. There he was formally greeted by the Polish church's bishops and prayers were said.

The meeting later with Gierek showed that the papal trip has its decidedly secular features, although the pontiff insisted when he arrived that his motivation for coming was "religious." Statements by the two men, also broadcast throughout the country, were warm and filled with expression of mutual respect.

Gierek offered the standard Soviet bloc position in support of disarmament measures such as the strategic arms limitation treaty and was critical of the proposed U.S. neutron bomb. He tied the church's pursuit of peace with the aim of the communist-run nation.

The pope, in response, touched more directly on internal Polish questions, including the country's badly troubled economy and the consequent threat of a national outburst of protest.

"I shall continue to feel in my heart," he said, "everything that could threaten Poland, that could be to her disadvantage, that could signify stagnation or crisis."

Also speaking of Poland, he said, "Peace and the drawing together of the people can be achieved only on the respect for the objective rights of the nation, such as the right to existence, the right to freedom . . ."

At the mass, there was a minor clash between the secular and religious strands of the occasion when a Polish Army band began to play a military anthem as the pope stood at the tomb of the unknown soldier while a choir sang Ave Marias in the background. The discordant confusion was quickly resolved.

A notable feature of the day's activities was how orderly they were.Special church-provided marshals shepherded the crowds while police stayed discreetly on sidestreets. No trouble was reported.

Early Sunday, after celebrating a youth mass, the pope is to travel by helicopter to the ancient capital of Gniezno, now an industrial town. He is expected to meet crowds there at least as large as those that filled Warsaw today. From there he will go to Czestochowa, the site of the Black Madonna, the holiest catholic shrine in Poland. CAPTION: Picture 1, The pope embraces the Catholic primate of Poland, Cardinal Stefan Wyszynski. AP; Picture 2, The pope returns his countrymen's greeting during the drive into Warsaw.AP Picture 3, Pope John Paul reviews an honor guard at Warsaw's military airport shortly after his return to his native land for a nine-day visit. Picture 4, Hundreds of thousands crowd into Warsaw's Victory Square for the pope's open-air mass. AP Picture 5 and 6, Pope John Paul II reaches out to a Polish girl, above, after holy communion yesterday in Warsaw's victory Square, then bends to embrace the child. AP