Pope John Paul II has warned the people in his homeland of the dangers of what he calls "freedom without responsibility" in the post-communist era. The pope made the comments in Krakow, before more than 2.5 million people at the largest ever open-air mass in Poland.

As the sun rose above Krakow's Blonia park, millions of worshippers shouted "thank you" and "long live the Pope" as they welcomed the leader of the world's Roman Catholics.

The frail, 82-year-old pope was often interrupted by shouts of approval from Polish Catholics, who regard him as the moral compass of a nation increasingly sour to a capitalist system since it abandoned communism 13 years ago.

Preaching to what experts say was the largest crowd ever assembled to hear him in Poland, the pontiff sought to encourage his countrymen not to lose their their faith in Christ at a time when the country is facing a harsh economic crisis.

His spiritual message was meant to console especially Poland's poor and jobless who are suffering under the country's daily burden of transition as it seeks to join the European Union in 2004. The pope also used his ninth and possibly, last trip home to warn of the dangers of freedom. He said that where "the noisy propaganda of liberalism, of freedom without truth or responsibility grows stronger, the shepherds of the church cannot fail to proclaim the one fail-proof philosophy of freedom," which he said was "the truth of the cross of Christ."

The pope's message appeared to play to growing sentiment among the nation's conservative Catholics that political decisions on issues such as liberalizing abortion to integrate Poland with western Europe will spoil their country.

He also seemed to refer to genetic engineering and euthanasia, saying that modern man often "lives as if God does not exist." John Paul said people often try to claim what he described as "the creator's right to interfere in the mystery of human life."

At the open-air mass the pope also beatified three Polish priests and a nun.

As church songs reverberated through the park, observers said the pope's spirits appeared strengthened by his journey back to Krakow, the medieval capital where he lived for 40 years. On Saturday, John Paul slept in his old bed, visited his old street, and drove by a site where he labored during the Nazi occupation in World War II. His nostalgic, four-day journey continued Sunday with a visit to the graves of his parents and brother, all dead more than half a century, and private prayers at the Wawel Cathedral, where he said his first mass as a priest in 1946.

While many feared that this trip would be the pope's last to Poland, Prime Minister Leszek Miller told reporters he had assured the Catholic leader that the country was ready to receive him at any time. Mr. Miller quoted the pope as responding: "Well, if God only allows."