When Pope Benedict XVI meets Spanish prime minister José Luis Rodríguez Zapatero this afternoon the politician will no doubt be welcoming and courteous to his papal visitor.
But in the seven years since the Socialist swept to power he has worked systematically to undermine the teachings of the Catholic church.
Mr Zapatero and his Socialist Workers Party party have presided over a nearly unrelenting march of secularism, often appearing to deliberately provoke the Vatican and Spain's Catholic establishment.
With 15 months of becoming premier, Mr Zapatero legalised same-sex marriage in a broad-ranging law that also extended adoption rights to homosexual couples. Large protests in Madrid were backed by the Catholic Church but ignored by the government.
Laws were also pushed through to drop religious education in state schools.
The Left-wing prime minister pointedly refused to attend an open-air Mass held by the Pope during a 2006 visit to Spain. Vatican sources bitterly complained that even Communist leaders like Fidel Castro and Daniel Ortega had attended the previous pope's masses as a mark of respect.
The government then fully legalised abortion - allowing terminations at 16 as long as the girl's parents are informed and permitting abortions on demand in the first 14 weeks of a pregnancy.
While Mr Zapatero makes no apologies for his secular ambitions, the country he leads has shed much of its traditional Catholicism organically.
Around 80 per cent of Spaniards describe themselves as Roman Catholic but only 25 per cent attend church regularly. Divorce was illegal until 1981 but now ends around 50 per cent of all marriages.
Premarital sex is common and the Church's teaching on contraception is regularly ignored.
Such is the Vatican's concern at the loss of one Europe's most traditionally Catholic countries that the Pope has made three visits since 2005, more than any other country except his native Germany.
For Spain's Catholics there are some reasons for optimism. Mr Zapatero announced in April that he will not stand in next year's general election, a contest the Socialists look likely to lose to the conservative People's Party.
The pace of his secular revolution has also slowed as his slumping popularity. Last year the government delayed a bill that would have required the removal of crucifixes from public places and ended state Catholic funerals.
Speaking at the time, theologian Juan José Tamayo said the government was already struggling against conservative opponents who hammered them over the weak economy. “They don't want to add more wood to the fire.”