It is insane that Christianity in the Third Millennium is still obsessed with sex as if it were the worst problem of mankind and the greatest of evils--so great that the Church feels the need to try to control it in considerable detail.
The Vatican has lately published a document on same-sex marriage: "Considerations Regarding Proposals to Give Legal Recognition to Unions between Homosexual Persons." The motive of this paper is to persuade governments to not legalize same-sex marriage. It is ironic that the long time defenders of pedophiles think they have the moral authority to tell the rest of us what is right and wrong about sexuality and family life.
The introduction states that "the arguments that follow are addressed not only to those who believe in Christ, but to all persons committed to promoting and defending the common good of society." Thus, this document pretends to give reasons and arguments that appeal to both Christians and non-Christians alike, but it does no such thing. In every case its reasons beg the question at issue and its arguments are blatantly circular.
Section I discusses the nature of marriage, according to the Church. It states "No ideology can erase from the human spirit the certainty that marriage exists solely between a man and a woman." If this were true, why don't we all believe it? It is not the certainty to pure reason that the Church pretends it to be. Moreover, it has not always been a certainty in the Church. Otherwise, how could the historian John Boswell have discovered Catholic and Orthodox liturgies for same-sex unions dating from medieval Europe? [see Same-Sex Unions in Premodern Europe, New York: Villard Books, 1994]
In the United States, it is a violation of the Constitutional principle of separation of church and state for the government to adopt religious arguments or use religious motives as the basis for law. It is also illegitimate for the government to disguise religious motives under the rubric of morality. There is no secular reason to withhold civil marriage from same-sex couples who wish to marry.
The Church would have the government of the United States promote and defend the Church's religious conception of marriage "as an institution essential to the common good." What the Church views as "the common good" includes people's "perception and evaluation of forms of behavior"--in other words, people's beliefs, in the present instant, about homosexuality. The Church is afraid that legalizing same-sex marriage will "obscure certain basic moral values." What it means by "basic moral values," of course, is the Catholic religious teachings about homosexuality. What the Church wants the government of the United States, and other governments, to do is to help promote Catholic teachings, something that is illegitimate for a secular government to do.