Spain used to be one of the most culturally conservative, devoutly Roman Catholic countries in Europe. Now Spain is about to pass a law legalizing homosexual marriage and adoption. When equally Catholic Belgium legalized gay marriage and adoptions, the Vatican, under Pope John Paul II, opposed the action with words. But Pope Benedict XVI, in the first policy test of his papacy, is going much further. A Vatican official told Spaniards that if the measure passes, they must defy it. Officials should refuse to marry same-sex couples or even process the paperwork if they try to adopt a child. Bureaucrats...