HAVANA (CNS) -- Preaching at Mass in Havana's Revolution Square, location of the headquarters of Cuba's Communist Party, Pope Benedict XVI called for full religious freedom and greater respect for human rights on the island.

"In Cuba steps have been taken to enable the Church to carry out her essential mission of expressing the faith openly and publicly," the pope said during his homily March 28. "Nonetheless, this must continue forward."

With President Raul Castro seated near the altar platform, the pope said, "I wish to encourage the country's government authorities to strengthen what has already been achieved and advance along this path of genuine service to the true good of Cuban society as a whole."

People started gathering for the Mass before 6 a.m. They prepared for the liturgy with songs and by listening to priests and a catechist explaining basic Church teaching on baptism and the Eucharist, the role of the pope in the Church and Pope Benedict's biography.

The Mass began at 9 a.m. under a clear blue sky with a light breeze blowing. As at the papal Mass in Santiago de Cuba March 26, thousands in the crowd were dressed in white T-shirts and baseball caps.

A priest led chants once the pope arrived and made his way in the popemobile through the crowd. One of the priest's louder inventions was "Benedicto, Benedicto, confirmanos en Cristo," ("Benedict, Benedict, confirm us in Christ").

In his homily, Pope Benedict said that faith in God and Jesus Christ is the key to salvation, true happiness and authentic freedom, and that the daily lives and work of committed Catholics can benefit the whole society.

The truth about the human person created in God's image and saved from sin by Jesus is the foundation of an ethical code that all reasonable people of good will can share, he said.

The ethical code "contains clear and precise indications concerning life and death, duties and rights, marriage, family and society, in short, regarding the inviolable dignity of the human person," he said.

"Cuba and the world need change," he said, but that will happen only if each and every person "is in a position to seek the truth and chooses the way of love, sowing reconciliation and fraternity."

The Catholic Church is not asking for special privileges in Cuba, but for the recognition of the basic right to religious freedom and freedom of expression, which includes expressing one's faith in concrete acts of charity and service to society, the pope said.

To carry out its obligations to proclaim and live the Gospel, he said, the Church "must count on basic religious freedom, which consists in her being able to proclaim and to celebrate her faith also in public, bringing to others the message of love, reconciliation and peace."

Pope Benedict said the Church's witness is usually expressed through "preaching and teaching," which is one of the reasons why the Church hopes that "the moment will soon arrive" when it can operate schools and universities in Cuba.

Catholics want to be witnesses of love and respond to evil with good, he said. "Let us walk in the light of Christ, who alone can destroy the darkness of error. And let us beg him that, with the courage and strength of the saints, we may be able -- without fear of rancor, but freely, generously and consistently -- to respond to God."

The Vatican had said Revolution Square could hold about 600,000 people and it was about three-quarters full when Mass began.

Msgr. Jose Felix Perez Riera, assistant secretary of the Cuban bishops' conference and pastor of St. Rita of Cascia Church, told Catholic News Service March 27 that many of the people who were to be at the Mass were being brought by the Communist Party and other government-related organizations, while many Catholics in towns outside Havana were unable to get tickets or transportation to the event.

One of the men in the crowd, 65-year-old Orlando Perez, said he was pleased to be at the papal Mass. Wearing a white T-shirt emblazoned with an image of Cuba's patroness, Our Lady of Charity of El Cobre, he said, "I am very happy because he is the vicar of God."

Asked how the crowd size compared with the number present in 1998 when Blessed John Paul II celebrated Mass in the same plaza, he said, "there are many more people here now."

Interviewed before the pope arrived, the man said he did not expect the pope to make demands of the government during the liturgy. "He speaks for the Lord; he's not a politician."

Asked what he wanted for the future, Perez responded, "I just want peace."