The problem with the same-sex marriage debate is that nobody (or almost nobody) is making the right argument.
On one side of the issue we have those who advocate for same-sex marriage, claiming that heterosexuals have the right to marry whoever they want and homosexuals should be allowed that also, out of fairness. On the other side you have people saying that homosexuality is a sin and thus should not be allowed. Both sides are making flawed arguments.
The problem with claiming that homosexuality is a sin is that whether or not it is a sin is irrelevant to making law. We live in a secular country, not a theocracy, and we don’t make everything that is wrong illegal – nor should we. Coveting, lust, and not remembering the Sabbath are sins, but I think we all agree that making and enforcing laws against these things would be bad.
In this country, laws are based on the concept of inalienable rights (also known as human rights or natural rights) – rights that all people have by virtue of being human and which government cannot grant or take away. These principles of inalienable rights are consistent with Christianity, but can stand alone as a justification that all people can agree with. What’s more, they offer an objective means of determining how government should be involved in making law about various issues.
Before we get into the arguments about same-sex marriage, we need to understand how government handles different behaviors and why. There are only 3 ways that government can treat behaviors. It can prohibit them, permit them, or promote them.
Because the highest purpose of government is the protection of inalienable rights, government should NOT prohibit behaviors that the people have an inalienable right to engage in. For example, we have the inalienable right to bear arms and thus government should not prohibit gun ownership. Government prohibition of something the people have a right to do creates an unjust law that itself violates inalienable rights.
On the other hand, government SHOULD prohibit behaviors that violate the rights of others. So, for instance, government must make murder and theft illegal because these behaviors violate inalienable rights. Any violation of inalienable rights should be prohibited by law in order to protect those rights.
However, there are many behaviors that are not a direct violation of inalienable rights. In such cases, government's main purpose (its secondary purpose, if you will) is the good of society. Thus, behaviors which are definitely bad for society should be prohibited while behaviors which are definitely good for society should be promoted. For example, driving very fast in a car may not always violate the inalienable rights of others (it only does if you hurt them or their property), but it is bad for society for people to be driving recklessly, so driving too fast is prohibited. On the other hand, government promotes giving to charity by providing tax incentives for doing so. Of course, it is necessary for the people to consent to any laws that limit their freedom through their representatives in government. But these are good laws that the people can pass on themselves for the good of society as long as the laws do not violate anyone's inalienable rights.
The default government position for behaviors is to simply permit them. Before a behavior can be prohibited, it is necessary to prove one of two things. You either have to prove that the behavior violates someone's rights OR you have to prove that it is bad for society and that prohibiting it does not violate anyone's rights. You can't just decide to prohibit something for no good reason or you violate the right to liberty.
Similarly, before you can promote a behavior you must prove that it is good for society and that it does not violate anyone's rights. You can't just go around promoting behaviors without good reason or you are not protecting the interests of society as a whole.
So that's the background. The question is, what is government's role with regard to different kinds of human relationships? Which behaviors should be prohibited? Which should be promoted? Which should be simply permitted?
Certainly some types of sexual relationships should be prohibited. Pedophilia, for example, is prohibited because it is harmful to children (and therefore society) and because it violates the inalienable rights of children (who cannot consent to sex).
Traditional marriage between a man and a woman has been promoted by government since the beginning because it is good for society. A traditional marriage is procreative, producing the next generation of citizens, and also forms a stable environment in which to raise those children, making them more likely to be good and responsible citizens. Thus, stable marriages are in society's best interest and government promotes this ideal by recognizing and protecting the marriage relationship and by providing economic incentives (such as tax breaks) to encourage people to marry and raise children in stable homes. It's an investment in the future.
In addition to producing the next generation, marriage forms both an economic and a social unit and provides benefits to society in this way as well. Economically, marriage is a wealth-building institution. Married people make more and save more than singles and children of married couples are far less likely to be poor. Socially, marriage is good for all parties – men, women, and children. Married men live longer and are happier and healthier than unmarried men. Women who are married and children who live with their married parents are far less likely to be abused. Children of married couples are more likely to do well in school. These are just a few of the many advantages of marriage to the individuals and to society as a whole.
By contrast, homosexual relationships do not provide these benefits to society. No logical conservative is advocating that we prohibit same-sex relationships between consenting adults. We don't cart people off to jail for engaging in consensual homosexual acts, nor do we want to. However, because same-sex relationships have not been shown to be a good for society, the proper role of government with respect to same-sex relationships is to simply permit them. Until same-sex relationships can be shown to have the same benefits to society as traditional marriage, we should not promote them.
Of course, some claim that same-sex couples have a right to marry. The problem with this claim is that there is no such right to marry whoever one wants. If there was such a right, then it would apply to many more than just homosexuals. Pedophiles who want to marry young children, zoophiles who want to marry animals, those who wish to marry close relatives, and those who want to marry multiple people would all have a “right” to do so if there is a right to marry whoever one wishes. I think we all agree that this is not the case. Civilization has always placed restrictions on marriage and it always will. The only question is what the proper restrictions are.
The thing is, marriage means much more than just two people that love each other or who want to commit to one another. Marriage is a natural unit based on the biology of human reproduction and, most importantly, the needs of children for care and stability. Only a union of a man and a woman can produce children naturally. Every child has just one biological mother and one biological father. And since both parents have equal responsibility for their child’s care, it is only natural that parents would form permanent unions in order to share that care and provide the stable home the child needs. Thus, every society on earth has figured out how to have marriages as individuals form a marriage relationship with another person of the opposite sex in order to raise a family together. There are lots of kinds of sexual relationships (committed or not), but only the permanent, exclusive, and comprehensive union of a man and woman produces a natural family unit.
Because the natural family is a natural unit, it has natural rights and responsibilities of its own that government should recognize in order to protect those rights. One of those rights, for example, is the right of parents to direct the upbringing of their children. If there is no such thing as a natural family with its own natural rights, then there is no such thing as parental rights. In such a case, every man, woman, and child is an individual ward of the state and has no natural family ties. This would also mean that parents bring up their children only by permission of government, which may be revoked at any time. In a society that is increasingly denying the existence of the natural family, it is no wonder that parental rights are also under attack.
One of the responsibilities of the natural family is that parents care for their children, providing food, shelter, love, and education. One of the advantages of this arrangement is that both the mother and the father bring different strengths to the parenting table which are both needed by the child. When one is missing, the child will be disadvantaged.
In addition to these profound reasons that marriage between a man and a woman is important to promote, there is the extremely important issue of children’s rights. One of the rights of children is to be cared for by their parents. Every child deserves to know and live with their biological mother and father. They also deserve to know where they came from and have a sense of their family history. Obviously, in an imperfect world, this doesn’t always happen, but it is an ideal worth holding up and encouraging in our society. That is why promoting traditional marriage is important in order to help as many children as possible to have this ideal in their lives.
But not only does a same-sex “marriage” not provide this ideal to a child, it actively undermines this ideal by encoding in law that children have no right to both of their parents and that children don’t need both a mother and a father. Thus, not only are children raised in same-sex household purposely deprived of either a mother or a father, but they are being told by the law and by society that they aren’t lacking anything - they have two parents, after all, and there is nothing about those parents’ genders that matters to their upbringing. But this is quite untrue. Children need and deserve both their mother and their father. Thus, same-sex marriage denies children their rightful parents inherently, as part of the design, not merely as a response to unavoidable circumstances as adoption does. And thus elevating same-sex relationships to the status of marriage unavoidably violates the rights of children and should not be made law.
In conclusion, it is because of the many benefits of traditional marriage to society as well as its intrinsic natural rights that government protects and encourages marriage. Same-sex relationships do not have the same status as marriage because they are intrinsically different relationships. Homosexual relationships are not a natural unit and can produce no children. They thus have no claim to the natural rights that marriage has. Since same-sex unions have not been shown to provide the benefits to society that marriage does, they are not and should not be encouraged the way marriage is.
Most importantly, in order to protect the rights of children to their mother and father, we must not pretend that same-sex relationships are marriages. We must not encode a vision of the family in our laws that denies children one of their parents as an inherent part of the design. We must uphold the ideal of a married mother and father for every child.