Pope Benedict XVI on Thursday exhorted an increasingly secular Spain to preserve the "treasure" of its Christian identity, strongly criticizing contemporary culture, DPA reported.
Young Catholics saw "the prevailing superficiality, consumerism and hedonism, the widespread banalization of sexuality, the lack of solidarity, the corruption," Benedict said.
The pope made the comments at Madrid airport after arriving on a four-day visit for World Youth Day celebrations.
Some young people suffered "open or hidden contempt or persecution" because of their Christian faith, and were deprived of "the signs of (Christ's) presence in public life," Benedict said.
Spain's Christian identity should be "cared for constructively," the pontiff said. "Although there are currently some reasons for concern, the greatest one is the desire for the betterment of all Spaniards," he added.
The dignitaries welcoming the pope at the airport included Prime Minister Jose Luis Rodriguez Zapatero, whose Socialist government has been at odds with the Vatican over its social reforms such as homosexual marriage, easier access to abortion and speedier divorce.
Zapatero is seen as favouring a greater separation between the church and state, though his government refrained from presenting a law to that effect in an attempt to improve relations with the Vatican.
The pope also indirectly expressed concern over the unemployment rate of more than 40 per cent among Spanish young people, saying they "look worriedly to the future, as they search for work."
An estimated 2,000 youth waving yellow-and-white Vatican flags were at the airport, representing almost 1 million pilgrims from about 190 countries who have converged on Madrid, according to government figures.
The city has been full of pilgrims in recent days, dressed in colourful T-shirts, carrying national flags, singing, buying papal souvenirs and seeking relief from the sweltering heat at the city's fountains.
The pope's visit has sparked some criticism for its cost, which is estimated at a minimum of 50 million euros (70 million dollars).
The authorities say most of this is covered by pilgrims' fees and sponsors. Critics, however, point to the deployment of 10,000 police, reduced transport fares for pilgrims and the use of public buildings such as schools to lodge them.
Thousands of people demonstrated against the papal visit on Wednesday. Police prevented them from clashing with Catholics wearing crucifixes and chanting "long live the pope."
Clashes later broke out between protesters and police. Eleven people, including two police officers, suffered slight injuries. Eight people were detained.
"They will not spoil the party for us," said Spanish Bishops' Conference spokesman Juan Antonio Martinez Camino.
The pope's visit to Madrid is his 21st trip abroad since he was elected pontiff in 2005, and his third to Spain. Benedict earlier visited Valencia in 2006 and Santiago de Compostela and Barcelona in November.