The natural structure of human sexuality makes man and woman complementary partners for the transmission of human life. Only a union of male and female can express the sexual complementarity willed by God for marriage. The permanent and exclusive commitment of marriage is the necessary context for the expression of sexual love intended by God both to serve the transmission of human life and to build up the bond between husband and wife (see CCC, nos. 1639-1640).

In marriage, husband and wife give themselves totally to each other in their masculinity and femininity (see CCC, no. 1643). They are equal as human beings but different as man and woman, fulfilling each other through this natural difference. This unique complementarity makes possible the conjugal bond that is the core of marriage.

Why is a same-sex union not equivalent to a marriage?

For several reasons a same-sex union contradicts the nature of marriage: It is not based on the natural complementarity of male and female; it cannot cooperate with God to create new life; and the natural purpose of sexual union cannot be achieved by a same-sex union. Persons in same-sex unions cannot enter into a true conjugal union. Therefore, it is wrong to equate their relationship to a marriage.

Why is it so important to society that marriage be preserved as the exclusive union of a man and a woman?

Across times, cultures, and very different religious beliefs, marriage is the foundation of the family. The family, in turn, is the basic unit of society. Thus, marriage is a personal relationship with public significance.

Marriage is the fundamental pattern for male-female relationships. It contributes to society because it models the way in which women and men live interdependently and commit, for the whole of life, to seek the good of each other.

The marital union also provides the best conditions for raising children: namely, the stable, loving relationship of a mother and father present only in marriage. The state rightly recognizes this relationship as a public institution in its laws because the relationship makes a unique and essential contribution to the common good.

Laws play an educational role insofar as they shape patterns of thought and behavior, particularly about what is socially permissible and acceptable. In effect, giving same-sex unions the legal status of marriage would grant official public approval to homosexual activity and would treat it as if it were morally neutral.

When marriage is redefined so as to make other relationships equivalent to it, the institution of marriage is devalued and further weakened. The weakening of this basic institution at all levels and by various forces has already exacted too high a social cost.

Does denying marriage to homosexual persons demonstrate unjust discrimination and a lack of respect for them as persons?

It is not unjust to deny legal status to same-sex unions because marriage and same-sex unions are essentially different realities. In fact, justice requires society to do so.

To uphold God's intent for marriage, in which sexual relations have their proper and exclusive place, is not to offend the dignity of homosexual persons. Christians must give witness to the whole moral truth and oppose as immoral both homosexual acts and unjust discrimination against homosexual persons.

The Catechism of the Catholic Church urges that homosexual persons "be accepted with respect, compassion, and sensitivity" (no. 2358). It also encourages chaste friendships. "Chastity is expressed notably in friendship with one's neighbor. Whether it develops between persons of the same or opposite sex, friendship represents a great good for all" (no. 2347).

Should persons who live in same-sex relationships be entitled to some of the same social and economic benefits given to married couples?

The state has an obligation to promote the family, which is rooted in marriage. Therefore, it can justly give married couples rights and benefits it does not extend to others. Ultimately, the stability and flourishing of society is dependent on the stability and flourishing of healthy family life.

The legal recognition of marriage, including the benefits associated with it, is not only about personal commitment, but also about the social commitment that husband and wife make to the well-being of society. It would be wrong to redefine marriage for the sake of providing benefits to those who cannot rightfully enter into marriage.

Some benefits currently sought by persons in homosexual unions can already be obtained without regard to marital status. For example, individuals can agree to own property jointly with another, and they can generally designate anyone they choose to be a beneficiary of their will or to make health-care decisions in case they become incompetent.

In light of the Church's teaching about the truth and beauty of marriage, what should Catholics do?

There is to be no separation between one's faith and life in either public or private realms. All Catholics should act on their beliefs with a well-formed conscience based on Sacred Scripture and Tradition. They should be a community of conscience within society. By their voice and their vote, they should contribute to society's welfare and test its public life by the standards of right reason and Gospel truth. Responsible citizenship is a virtue. Participation in the political process is a moral obligation. This is particularly urgent in light of the need to defend marriage and to oppose the legalization of same-sex unions as marriages.

Married couples themselves, by the witness of their faithful, life-giving love, are the best advocates for marriage. By their example, they are the first teachers of the next generation about the dignity of marriage and the need to uphold it. As leaders of their family—which the Second Vatican Council called a "domestic church" (Lumen Gentium, no. 11)—couples should bring their gifts as well as their needs to the larger Church. There, with the help of other couples and their pastors and collaborators, they can strengthen their commitment and sustain their sacrament over a lifetime.

Conclusion

Marriage is a basic human and social institution. Though it is regulated by civil laws and church laws, it did not originate from either the church or state, but from God. Therefore, neither church nor state can alter the basic meaning and structure of marriage.

Marriage, whose nature and purposes are established by God, can only be the union of a man and a woman and must remain such in law. In a manner unlike any other relationship, marriage makes a unique and irreplaceable contribution to the common good of society, especially through the procreation and education of children.

The union of husband and wife becomes, over a lifetime, a great good for themselves, their family, communities, and society. Marriage is a gift to be cherished and protected.