To see this more clearly, it’s important to understand the notion of “sexuality”. The CCC teaches that “Sexuality affects all aspects of the human person in the unity of his body and soul. It especially concerns…the capacity to love and to procreate, and… the aptitude for forming bonds of communion with others.” (CCC 2332
The CCC goes on to explain that “everyone, man and woman, should acknowledge and accept his sexual identity. Physical, moral, and spiritual difference and complementarity are oriented toward the goods of marriage and the flourishing of family life.” (CCC 2333
“Each of the two sexes is an image of the power and tenderness of God, with equal dignity though in a different way.” (CCC2335
So every man is born male, and every woman is born female – the male sex predominantly representing the power of God, and the female, the tenderness of God. So, “The union of man and woman in marriage is a way of imitating in the flesh the Creator’s generosity and fecundity.” (CCC 2335
Now, the homosexual act, not being a complementary union of the two different sexes, is utterly closed to the gift of life, and therefore can never be condoned.
However a person with same sex-attraction is, like any other, a beloved child of God. The first point of reference for anyone should be
God. A loving creator and father who made each one of us in his image, with whom to have a personal relationship.
But then don’t homosexuals have the right to be happy too?
The answer is of course, yes. But this happiness is found in the primary goal of fulfilling God’s will for their lives, not in the pursuit of sexual pleasure or affection in another person of the same sex. The Church teaches that homosexuals are called to love and to serve God in chastity, and "By the virtues of self-mastery that teach them inner freedom, at times by the support of disinterested friendship, by prayer and sacramental grace, they can and should gradually and resolutely approach Christian perfection." (CCC 2359)
Second! Homosexual Union ≠ Heterosexual Union
It is a mistake to think that homosexual union equates in any way to heterosexual union. They are both foundationally and inherently different.
“The marriage covenant, by which a man and a woman form with each other an intimate communion of life and love, has been founded and endowed with its own special laws by the Creator. By its very nature it is ordered to the good of the couple, as well as to the generation and education of children.”(CCC1660
So marriage is not just an institution written into societal law, but is something much more primordial. It’s very nature is to exist for the flourishing of man and woman together in communion with God and for the continuation of life.
It thus transcends the domain of social constructs; it is a a sacred institution, willed and ordained by God, which men do not have the power to redefine. The laws of God are not subject to the laws of men.
So even if homsosexual marriage were to be written into the laws of men, they would still never be anything other than a civil union, since marriage, by it’s very definition, is a sacred institution that unites one man to one woman, and always will be.
Furthermore, it is a sacrament, which “signifies the union of Christ and the Church. It gives spouses the grace to love each other with the love with which Christ has loved his Church; the grace of the sacrament thus perfects the human love of the spouses, strengthens their indissoluble unity, and sanctifies them on the way to eternal life.” (CCC 1661
by its very nature is heterosexual.
With the secular mentality rapidly tearing through the world, the monumental challenge now lies before for the Catholic Church to communicate the Lord’s Word to our brothers and sisters outside of the faith.
This is something that every one of us is called to do in our own small way. Let us never cease to proclaim his Glory to all, as we draw strength from our Lord’s words at this unsettling time:
Blessed are those who are persecuted in the cause of uprightness: the kingdom of Heaven is theirs.” (Matt 5:10-12)