A - Thanks for asking. I hope to give a good answer, so I ask you to prayerfully consider reading and praying about the entire post, which will be somewhat long, because we have a lot to cover.
There are several reasons the Catholic Church opposes same-sex marriage and I will get to those below. But, first we must explore what the Church teaches marriage is all about. Here is what the Catechism says Holy Matrimony is about:
1601 "The matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life, is by its nature ordered toward the good of the spouses and the procreation and education of offspring; this covenant between baptized persons has been raised by Christ the Lord to the dignity of a sacrament.There is a two-fold purpose to marriage - the union of the spouses and procreation. Sometimes we call this babies and bonding. Same-sex marriage cannot fulfill either of these purposes. Same sex marriage, by its very nature, is an infertile relationship that does not naturally produce children. Also, men and women are, again by nature, complimentary to one another in many ways - physically, emotionally, psychologically, etc. Men and women do not share the same biology and together they make up both ways you can be human. Therefore, the only way to complete a fully "human" relationship is to have both sexes.
Reason #1 - The family. No matter how much someone may want it to happen - a man cannot be a mother or wife and a woman cannot be a father or husband. Yet, this is exactly the kind of experiment we are now conducting in our culture with same-sex relationships (and the children in these homes).
In a society that does not see the purpose of marriage as any thing more than a social construct that can be re-imaged into whatever we want, we start to tear down the basic building block of society - the family. This creates numerous issues, which are not being discussed much right now. Including the destabilization of parenting. What happens when children are brought into same-sex marriages? In countries such as Canada, they now have to deal with children with three natural gaurdians - (e.g., one birth father, one birth mother, one mother by adoption). When same sex marriages then end (and they do at a much higher rate), think of the ramifications on the children. They now have three parents who share visitation and rights of the children. What confusion for the child!
REASON #2 - Society. Strong traditional families make strong homes, which make a strong society.
We already know that divorce causes more single family homes -> this leads to more to more women caring for children -> which leads to poverty.
Other benefits to traditional marriage include (according to research - see footnotes):
- Less poverty
- Happier homes and individuals
- Better health
- Less crime
Families thrive in stable families from traditional marriages. The government should focus on improving these families and helping strengthen opposite sex marriages - not undermine them. Work on reforming divorce laws, not just believing they have to stay as-is.
When no-fault divorce was implemented, divorce skyrocketed. It gave people an easy "out" from their marriage. This will no doubt be the case if we continue to undermine marriage or try to re-define it. Couples who stay married, and then work on their marriage, can grow as people and families. Couples that divorce don't "fix" any of the underlying issues and studies show they bring the same problems into new relationships. No-fault divorce didn't help anybody, esp. the children involved.
REASON #3 - True love. You here it constantly argued that we shouldn't stop two people who love each other from expressing their love in marriage. This is bad logic. First of all, we need to define what love really is. Love = choosing what is best for the other despite the cost to myself. If we truly want what is best for another person, then we would never advocate same-sex marriage, because it takes a risk with another person in every realm of their life - mentally, socially, spiritually, physically, etc. Same-sex marriage and homosexual sex is not real love. While we may have true feelings for another, we cannot truly love them according to the definition above.
So, the question then becomes - what good would come from same sex marriage? I see none. Some argue it is a matter of "equality". But, this is clearly not the case. The law recognizes marriages because society benefits from a husband and wife staying together to raise kids. So, giving preference to this kind of relationship is for the common good of all of society. There is no "right" to marry whomever or whatever you like. If there was, who are we to stop a mother and son from marrying? A man and a dog? Five women? Where would it stop?
The health and prosperity of our culture is at risk and the institution of marriage needs to be protected. It is not bigoted, homophobic, narrow-minded, irrational, or ignorant to think this is the case.
We have a lot to lose if marriage continues to crumble.
***As one final side note, the Catholic Church calls us to treat persons with same-sex attraction with openness and true love. They should not be marginalized, harassed or abused in any way. This is not the Christian answer. We should offer support and prayers. We should offer a road to chastity - which all of us are called to - and help them achieve it through groups such as Courage. Even if we get attacked for doing so.
For more details on these issues, I recommend this link.