LISBON, Portugal — In his most thorough admission of the church's guilt in the clerical sex abuse scandal, Pope Benedict XVI said Tuesday the greatest persecution of the institution "is born from the sins within the church," and not from a campaign by outsiders.
The pontiff said the Catholic church has always been tormented by problems of its own making – a tendency that is being witnessed today "in a truly terrifying way."
"The church needs to profoundly relearn penitence, accept purification, learn forgiveness but also justice," he said.
"Forgiveness cannot substitute justice," he said.
Benedict was responding to journalists' questions, submitted in advance, aboard the papal plane as he flew to Portugal for a four-day visit.
In a shift from the Vatican's initial claim that the church was the victim of a campaign by the media and abortion rights and pro-gay marriage groups, Benedict said: "The greatest persecution of the church doesn't come from enemies on the outside but is born from the sins within the church."
Previously, he has taken to task the abusers themselves and, in the case of Ireland, the bishops who failed to stop them.
Benedict has promised that the church would take action to protect children and make abusive priests face justice. He has started cleaning house, accepting the resignations of a few bishops who either admitted they molested youngsters or covered up for priests who did.
Critics are demanding more. They recall that while Benedict has scolded his church and accepted some bishops' resignations, none of them has been actively punished or defrocked, even those who admitted molesting children.
"Many are tiring of hearing about his 'strong comments.' They want to see strong action," said David Clohessy, director of the main U.S. victims' group, the Survivors Network of those Abused by Priests.
Portugal has reported no cases of abuse, and the pontiff was expected to address other issues during his appearances here, especially the neglect of Christian values.
After staying in the capital, the 83-year-old pope was due to go to the shrine at Fatima, in central Portugal, on Wednesday and to Porto, the second-largest city, on Friday.
At least 500,000 people are expected to attend his Mass in Fatima on Thursday, the anniversary of the day in 1917 when three Portuguese shepherd children reported visions of the Virgin Mary.
Church bells rang out in Lisbon as the pontiff proceeded through the Atlantic port city in his popemobile. Several thousand people lined the streets on a showery day, many shouting, "Viva o Papa!" Some stretches of the route were thinly attended, however.
Portugal is nearly 90 percent Catholic, but only around 2 million of its 10.6 million people describe themselves as practicing Catholics. In recent years, Portugal has drifted away from the church's teachings.
Its center-left Socialist government passed a law in 2007 allowing abortion. The following year, it introduced a law allowing divorce even if one of the spouses is opposed. It said the legislation was part of Portugal's "modernization."
Benedict, who has expressed concern about the forfeiture of traditional values in Europe, sharply criticized Portugal's abortion law in remarks at Lisbon airport. He also decried the failure of public officials to uphold the sanctity of life.
"The point at issue is not an ethical confrontation between a secular and religious system, so much as a question about the meaning that we give to our freedom," he said.
The pontiff's visit coincides with another tense moment between the elected authorities and the church.
Conservative President Anibal Cavaco Silva has to decide by next week whether to veto or ratify a bill passed by Parliament that would make Portugal the sixth country in Europe allowing same-sex couples to marry.
Benedict did not comment on that development, but he returned to his criticism of the financial and economic crisis which, he said, demonstrated the need for "an ethical component" in running the global financial system. His 2009 encyclical, "Charity in Truth," outlined his vision for greater moral responsibility in the economy.
Portugal is western Europe's poorest country and many have suffered acute hardship after the global downturn. Portuguese bishops last year drew attention to what they called "scandalous levels of misery" in the country.
Cavaco Silva said the pontiff had arrived at a time of uncertainty that was testing Portugal's strength as a community.
"In these times, men require someone bearing a message of hope to meet their thirst for justice and solidarity," he told the pope.
Benedict attended a welcome ceremony at the 16th-century Jeronimos monastery and church in the Lisbon suburb of Belem, which means Bethlehem in Portuguese.
Inside the vaulted Jeronimos church, the pope stood and watched a children's choir sing, giving a nod of appreciation. The pontiff knelt and crossed his hands on a gold and crimson cushion to pray in the silent church.
Jeronimos was built to celebrate the feats of Portuguese maritime explorers who were the first Europeans to set foot in parts of Africa, India and Latin America. The Crown was allied with the Catholic church on those voyages which, as well as endowing Portugal with huge wealth, also sought to convert natives they encountered.
"Portugal has gained a glorious place among the nations for service rendered to the spreading of the faith: in all five continents there are local churches that owe their origin to the Portuguese missionary activity," the pope said at an evening open-air Mass in Lisbon's main riverside square, Terreiro do Paco. Officials said 150,000-200,000 people attended the celebration.
Some 10,000 children from the civic movement Eu Acredito ("I Believe") stood next to a special altar for the pope.
Associated Press writer Nicole Winfield contributed to this report.
On the Net:
Papal visit in various languages: . http://www.bentoxviportugal.pt
Official Fatima shrine page: http://www.fatima.pt