Valencia, Spain - Pope Benedict XVI arrived Saturday in Spain for a brief but charged visit to register the church's opposition to gay marriage and Europe's long slide into secularism.
"Rapid secularization" and pretending God does not exist "compromises the future of culture and society," the 79-year-old pope said in a written message to Spain's bishops.
Perhaps nowhere in Europe are tensions between church and state as strong as in Spain, a once solidly Roman Catholic nation that is particularly important to the church. And, even amid the pomp of a papal visit, neither side is hiding the frictions.
Over the last two years, the church has grown increasingly dismayed over the policies of the Socialist prime minister, José Luis Rodríguez Zapatero, who last year legalized gay marriage and has loosened laws on divorce and medically assisted fertilization. Last week, two Spanish soldiers, both men, announced plans to be married this summer.
But disagreement over policy spilled over into the personal when Mr. Zapatero's office said this week that he would not attend the pope's outdoor Mass here Sunday, which is expected to attract a million or more people. His office did not explain the decision, which ballooned into front-page news here and in Italy.
The Vatican, which normally seeks to smooth over all embarrassment, reacted with unusual force, commenting that other leftist leaders had attended such Masses when Pope John Paul II visited their countries.
"Ortega went to the Mass, Castro went to the Mass," the pope's spokesman, Joaquín Navarro-Valls, pointed out to reporters on the flight from Italy, referring to the Communist leaders of Nicaragua and Cuba, Daniel Ortega and Fidel Castro.
On Saturday morning, Mr. Zapatero greeted the pope at the airport, as did King Juan Carlos, and a huge crowd chanting "Viva El Papa!" Mr. Zapatero called on the pope briefly in the early evening.
Benedict, on his third trip outside Italy since becoming pope last year, was in Valencia to attend a conference on the family. Tens of thousands of Catholics from around the world have come to this seaside city in eastern Spain to attend.
The papal visit is scheduled at a short 26 hours. But the subject of the family encompasses scores of issues vital to the church, including its teaching that marriage must be between a man and a woman and its opposition to divorce and abortion. Some of the people at the conference here were wearing T-shirts showing a sperm penetrating an egg with the caption: "My first day of life."
Last month, a document issued by the Vatican office concerned with families condemned gay unions with particular force, calling them a sign of "the eclipse of God." And while Valencia gave the pope a rousing welcome — with yellow-and-while papal flags draped from windows and balconies, and tens of thousands of people lining the streets and crowding onto highway overpasses — gay groups have protested the visit.
Benedict's comments on the trip seemed aimed at expressing the church's view that marriage must be between a man and a woman without outright condemnation, but with absolute clarity.
"Let's not start with the negative," he told reporters on the plane, when asked about how church teaching squared with the reality of Spain's law allowing same-sex marriage.
"It's true that there are problems and things that Christian life says no to," he said in Italian. "We want to make people understand that according to human nature it is a man and a woman who are made for each other and made to give humanity a future.
"Let's shine a light on the positive things, so we can make people understand why the church cannot accept certain things but at the same time wants to respect people and to help them," he added.
By evening, several hundred thousand people gathered at the futuristic City of Arts and Sciences, as Benedict elaborated on the importance of families as central to human beings' love for one another and as the basic structure that gives a society its strength.
His message ranged from domestic concerns, urging parents to avoid bickering and to love their children, to an appeal for governments to "reflect on the evident benefits" of happy and peaceful families. At several points, he stressed that marriage is a matter between "man and woman" or "husband and wife."
He said, "This meeting provides a new impetus for proclaiming the gospel of the family, reaffirming the strength and identity of the family founded on marriage and open to the generous gift of life, where children are accompanied in their bodily and spiritual growth."
He added, "This is the best way to counter a widespread hedonism, which reduces human relations to banality and empties them of their authentic value and beauty."
Although Spain has a strong Catholic tradition, it has recently been moving away from the church, like much of Europe.
A recent survey showed that 80 percent of Spaniards considered themselves to be Catholic, yet only 18 percent attended Mass regularly on Sundays or religious holidays. This drift, evident around Europe, has been a particular concern over many years for Benedict — made perhaps more important in Spain as a touchstone for hundreds of millions of Catholics in Spanish-speaking countries in South America.
"You know that I follow closely and with much interest the life of the church in your country, a country with deep Christian roots, one which has greatly contributed and must still contribute to the proclamation and spread of the faith," Benedict wrote in his message to the bishops.
Despite the spirited welcome Valencia gave the pope, the city remained in a mourning, after 42 people were killed here when a subway train derailed this week. Benedict's first stop after arriving here was the Jesús Street metro station, where the accident happened. He prayed and laid a wreath, and later comforted weeping family members in Valencia's cathedral.