Same-sex marriage is being allowed based on the idea that marriage is a matter of individual conscience, and as such individuals who practice homosexuality should have the same rights to enter in to marriage as those who do not practice homosexuality.
What is being ignored in this debate is the question of what is the government's role in marriage? Why is marriage an issue of public policy at all? If marriage is simply a matter of individual conscience (i.e. people should be able to marry who they want to) then what basis does the government have for limiting any type of marriage? If we are going to assume individual conscience is the guiding principle for who should be able to get married, then we must soon start repealing laws against polygamy, marrying family members, marrying animals, corporate marriages, marrying fictional characters and the list goes on. To be honest, I don't know if there are laws against all of those things, but I can imagine that human creativity and perversity will force those issues sooner or later.
If, you say, the government's interest is to protect people from inappropriate sexual relationships, I would point out that our society has almost completely removed sexual relations as an legal interest in marriage. Marriage is not legally required for anyone to have sex in any way imaginable. Marriage partners are not legally bound to respect the sexual norms associated with the tradition of marriage (i.e. marital faithfulness). There are laws against sexual acts that are seen as a violation of those who do not consent (or are deemed unable to consent with understanding). But even these laws are applied unevenly and without a well thought out ethical consideration. In society's mind some things are still "just wrong." I highly doubt that many people could give an ethical argument for why unwed consensual teenage sex is legal but child pornography is not, yet it seems the majority opinion is that one is okay (or even necessary) while the other is an abomination that requires the shame of going on a permanent, public database with a mugshot and address for the perpetrator. If children cannot responsibly give consent it should not matter who they are giving the consent to. Just because other children are doing the abusing it doesn't make the abuse any less.
Returning to my point, if we are going to have any marriage laws at all we need to have a basis for doing so. The debates have been about rights and equality, but few have addressed the real question underlying these laws--the relationship of the government, the individual and the community.
If those were the terms of the debate then we could talk with reason.
As a Christian I believe that homosexual activity is a sin. I see it as a perversion of the gift of sex that God gave us for the purpose of pleasure and procreation. I do not deny that some individuals may struggle more than others with a temptation toward homosexuality even to the point of feeling "born this way." It is clearly observable that many (most?) struggle with a temptation toward adultery and pornography and all sorts of other sexual perversion, but the presence of those temptations do not make them "natural" in the sense of being acceptable before God. While it may seem cruel for me to ask others to deny themselves the pleasures they feel they were born to posses, we must recognize that we do this all the time. The entire justice system is built on the idea that we must persuade people to restrain themselves from doing what they might feel they were born or compelled to do. I see homosexual activity as a sin that is an affront to God and damaging to those who participate. Because of this belief I would encourage people to find a way to avoid or flee that lifestyle, but I also recognize that it is not currently illegal (in most places). So I can speak in one way about my moral beliefs as a Christian, but what should I say as an American Citizen?
First, my moral beliefs are relevant when it comes to discussions of public policy. Even without evoking the Bible or my personal religious practices, I have a right to speak and promote what I feel is right and wrong for others to do. Liberty is the word we use for freedom in America, but to imagine that all individuals are free to do as they want is logically impossible. Liberty in America must mean a willingness to accept responsibility as a citizen of the People. Ultimately, it is the freedom of the People that is protected by the constitution, not merely the freedoms of the individual. I know that is a radical interpretation that has lots of implications for other debates, but that's how I see it. It is on this point, I believe, that democracy is most vulnerable. There is no final standard for values. The people must decide to agree, or else democracy fails. There is no king to go to to resolve disputes. There is no American Standard Moral Code. We have to agree, compromise, or fight ourselves into oblivion.
Second, as an American I have an interest in a public policy that brings stability to our society. The cold hard scientific evidence shows that traditional families are good for our society. Traditional families promote less crime, higher education rates, higher employment rates, better health, more stable markets. I believe that same-sex marriage is a change to marriage law that will benefit neither traditional marriage couple or same-sex couples. The results will be higher family instability, confusing and damaging legal situations, emotionally scarred children, an increase in divorce, and a decrease in the marriage rate. See AN ECONOMIC ASSESSMENT OF SAME-SEX
MARRIAGE LAWS by DOUGLAS W. ALLEN from Harvard Journal of Law & Public Policy [Vol. 29].
In spite of my ethical and philosophical approach to the idea of marriage I know that most peoples' opinion boils down to a simple statement we hear all the time. "If two people love each other, who am I to tell them not to get married?"
This simple statement is hard to argue against persuasively because it appeals to our American ideal of "live and let live" and an echo of romanticism that still drives pop culture (even though "love" itself has little real meaning beyond a commercial drive for fulfillment. Love, for the masses, is a tool that corporations use to sell their products). We want to agree with the statement, yet a critical eye can see the problem right away. We are not debating love. We are debating legal marriage. There have never been laws dictating whom you can love. Those would be unenforceable. We are not even debating laws about sex, adoption, benefits, photographers, cakes, etc. We are talking about marriage. If two people love each other great for them. When it comes to marriage, the law has it's own requirements and none of them are love. As far as the government is concerned marriage is an institution that simplifies a common situation of a man and woman wanting to unite a household, to support each other economically, and most importantly potentially raise children in a safe and stable environment. Alternate definitions of marriage threaten the intended public policy purpose of marriage. All the laws that currently apply to marriage will be complicated as they must be applied to situations they were not designed for. Future laws concerning marriage will be difficult to craft as they will need to account for all the different circumstances that will (eventually) be considered a legal marriage. The impact on future generations will not be worth the feeling of liberty experienced by a few.
My heart goes out to all of those affected by this non-debate. I don't doubt most people's sincerity. I can see that many people feel that they are standing up for what is right. I understand that there are real injustices going on against people who practice homosexuality. I don't deny that the pain is real or that rejection hurts. I'm sorry for that. Honestly, I see ways we could mitigate that pain somewhat in our society, but I don't think this shift in our thinking about marriage will result in less pain for the people of our society. On the contrary, I am convinced that because of this more people will suffer.