How should one regard Church recognition of [so-called] same-sex marriages, as argued and practiced by some Protestants?
Answer: To clarify the Catholic position on the question of same-sex relationships, I reproduce here the main statements (in an unofficial translation) from the Katholischer Erwachsenen Katechismus (Catholic Adult Catechism) (Band 2: Leben aus dem Glauben [Freiburg: Herder, 1995], pp. 385-87).
The legal regulation of same-sex (i.e. homosexual) relationships should not be confused with the moral evaluation of homosexual acts. Homosexuality is a multi-faceted phenomenon. Attempts to dissect the homosexual phenomenon into various forms and to describe its origins and development, as well as the degree of homosexual orientation, indicate just how controversial research into homosexuality and its characterisation is even in modern psychology and medicine. Differing opinions regarding the form and development of homosexuality reveal that a distinction needs to be made between homosexual orientation and homosexual acts. Homosexuals themselves come to recognise their sexual orientation or tendency as permanent only within the scope of different phases of development. Those with a homosexual orientation have not chosen this themselves (cf. Catechism of the Catholic Church, no 2358). Medical research into homosexuality still maintains the view that the homosexually oriented cannot change this tendency. On the other hand, acknowledged medical writers point out that, under favourable conditions, certain therapies can permanently change a homosexual orientation. Whatever can be said from a medical point of view regarding homosexual orientation or tendency, from an ethical point of view, it is clear that the homosexual is no more responsible for their homosexual behaviour than a heterosexual is responsible for their heterosexual behaviour. That is significant not only from the perspective of basic ethical considerations but also in regard to the threat to health from a possible transfer of the HIV virus, which is possible through homosexual acts as well as through heterosexual acts.
Homosexuality brings drawbacks compared to heterosexuality. Even the anatomy of sexual organs points to the duality of the sexes. Homosexual acts fundamentally rule out a complete sexual polarity as well as procreation. Therefore, a same-sex relationship implies infertility. From this perspective, the homosexual also perceives their orientation as being different even if they have reconciled themselves to this predetermination.
From the perspective of the order of creation and from Gods instruction to man and woman to procreate, homosexuality cannot be regarded as equal to heterosexuality. According to the Bible, the real room for full sexual union is marriage between a man and a woman, and marriage is the germ cell of human society.
Homosexuality was strongly condemned in biblical times. The Bible was clear in both the Old and the New Testament that homosexual practices cannot represent the actual purpose of human sexuality. In Israel people who consummated homosexual acts – for whatever reason – were even cast out by the people according to the law (cf Lev 18:22; 20:13). In the New Testament the Apostle Paul interprets homosexual behaviour as unnatural intercourse (cf Rom 1:15-27; 1 Tim 1:10), which he warns against in the same way that he warns against other sexual wrongdoing.
In the past a lack of knowledge regarding the causes of homosexuality led to persecution and condemnation. Today’s insight into the development of homosexuality prohibits any defamation of homosexuals. From an ethical point of view, it is important for homosexuals to make an effort not to let their sexuality control them, but instead consciously integrate this into humane moral concepts and purposes. Above all, they must respect their human dignity and must not misuse their homosexuality as a means to satisfy their own sexual drive. They must avoid causing offence by their behaviour and seducing others. They are called to fulfil Gods will in their lives and, if they are Christians, to unite to the sacrifice of the Lords Cross the difficulties they may encounter from their condition. (Catechism of the Catholic Church, n. 2358).
In society all people have a duty to treat homosexuals with sympathy. Defamation and degradation drives them into an intolerable situation and hampers communication. Christians are called to offer homosexuals pastoral care. Same-sex partners cannot obtain Church recognition as an institution.