Faced with the fact of homosexual unions, civil authorities adopt different positions. At times they simply tolerate the phenomenon; at other times they advocate legal recognition of such unions, under the pretext of avoiding, with regard to certain rights, discrimination against persons who live with someone of the same sex. In other cases, they favour giving homosexual unions legal equivalence to marriage properly so-called, along with the legal possibility of adopting children.
Where the government’s policy is de facto tolerance and there is no explicit legal recognition of homosexual unions, it is necessary to distinguish carefully the various aspects of the problem. Moral conscience requires that, in every occasion, Christians give witness to the whole moral truth, which is contradicted both by approval of homosexual acts and unjust discrimination against homosexual persons. Therefore, discreet and prudent actions can be effective; these might involve: unmasking the way in which such tolerance might be exploited or used in the service of ideology; stating clearly the immoral nature of these unions; reminding the government of the need to contain the phenomenon within certain limits so as to safeguard public morality and, above all, to avoid exposing young people to erroneous ideas about sexuality and marriage that would deprive them of their necessary defences and contribute to the spread of the phenomenon. Those who would move from tolerance to the legitimization of specific rights for cohabiting homosexual persons need to be reminded that the approval or legalization of evil is something far different from the toleration of evil.
In those situations where homosexual unions have been legally recognized or have been given the legal status and rights belonging to marriage, clear and emphatic opposition is a duty. One must refrain from any kind of formal cooperation in the enactment or application of such gravely unjust laws and, as far as possible, from material cooperation on the level of their application. In this area, everyone can exercise the right to conscientious objection. – From Considerations Regarding Proposals to Give Legal Recognition to Unions Between Homosexual Persons (2003)