The Church opposes some of the Socialists' liberalising reforms
Hundreds of thousands of people have attended an open-air Mass in central Madrid aimed at promoting family values in defiance of some government reforms.
Pope Benedict XVI addressed the Catholic congregation via giant video screens, urging people to keep family values strong.
Spain's Socialist government has legalised gay marriage and made divorce easier, angering Catholic clergy.
The Archbishop of Madrid used the Mass to condemn abortion.
Archbishop Antonio Maria Rouco Varela , quoted by the AFP news agency, spoke of the "shocking cruelty" of abortion, warning against the "culture of death".
Spain's government is considering easing the country's restrictions on abortion.
The Pope told Spanish families on Sunday: "Do not let love, openness to life and the incomparable links that join your homes weaken".