Pope Benedict XVI's made a comment about gay marriage and said that it was one of several threats to the traditional family. Reuters reported that he said it undermined "the future of humanity itself."
Protesters outside St. Peter's square, angered by the Pope's comments, held signs that said things like "Marriage of All" and "Homophobia (equals) death," reported The Associated Press.
The Pope also called abortion a threat to peace, along with gay marriage, during his annual peace message that was released by the Vatican on Friday.
The AP reported that organizers of the protest issued a statement that said, "Gay unions don't harm peace. Weapons do."
The Pope also said that "pride of place goes to the family, based on the marriage of a man and a woman. This is not a simple social convention, but rather the fundamental cell of every society. Consequently, policies which undermine the family threaten human dignity and the future of humanity itself," he said.
Around the world, Catholic officials have protested against gay marriage. In the U.S. one of the leaders against gay marriage is New York Archbishop Timothy Dolan, reported Reuters. He fought against gay marriage before it was legalized in New York state and he sent a letter to President Obama criticizing the move to not support a federal ban of gay marriage.
"The Roman Catholic Church, which has some 1.3 billion members worldwide, teaches that while homosexual tendencies are not sinful, homosexual acts are, and that children should grow up in a traditional family with a mother and a father," reports Reuters.
In Europe, gay marriage is legal in a number of countries including the Netherlands and Spain and in some churches they allow gay marriage, gay clergy, femail priests and gay bishops, reports Reuters.