Homosexual marriage is an American inevitability. To paraphrase Seth McFarlane, creator of one of the most controversial and socially impacting television shows, Family Guy, every movement to deny rights to groups of people in this country has failed. The Suffrage Movement gave women the right to vote, the Civil Rights Movement ended Jim Crowe laws, and the Gay Rights Movement will give homosexuals the right to marry. This is because anything that the American people has designated as a "right", according to our Constitution, must be made available to all Americans.
Marriage, in it's inception, was created as a way to establish methods of tracking the inheritance of wealth and property. If a woman bore children for one man, then those children would be eligible to inherit his property. In fact, when a woman married, she was considered property. In essence ownership of this woman transferred from father to husband. Incidentally, this is why a woman's last name changed after marriage. However, the concept of marriage has evolved over time.
Nowadays marriage is a combination of finances, as well as a public declaration of a couple's commitment to one another. If we remove the sentimentality from marriage, we can see that there are many advantages for a couple to be married. For one, marriage affords two previously unrelated people the benefits of being family. This includes the right to visit one another in the hospital, make important health related decisions, and be involved in death related decisions. Moreover, tax breaks, and the ability to share insurance plans are afforded to married couples. Whereas unmarried couples are legally prohibited from engaging in most of these benefits.
There was a time, not so long ago, when these benefits were being kept from more than same sex couples. There are many living people who remember a time when inter-racial marriages were seen as unnatural, and contrary to God's wishes. In the end, the government and the people decided that any right afforded to any American must be afforded to ALL Americans, regardless of race or religion.
If we take a look at the laws that used to govern marriage, we can see that monarchs were usually the people who were the creators of the law. The founding fathers of this country, however, saw that a monarch wasn't privy to needs of every section of it's nation. To solve this problem they decided that certain areas of governance would be up to the individual state. Marriage is one of these institutions. Moreover, the founding fathers understood that there was no place for religion in the halls of governing, and instituted a policy within the Constitution which separated The Church and The State.
The arguments against homosexual marriage remain based in religious beliefs. Popular tag lines referring to Creation Theory, specifically "Adam and Eve not Adam and Steve", are steeped in religious ideology. People, of course, are entitled to believe what they want to believe, but in the rooms where law is made and decided upon, God is not to be a part of the discussion. Therefore, the arguments that gay marriage is against God are moot because He is not part of the conversation. The only thing which is to be discussed is why an institution that is afforded to one person is not being afforded to ALL people.
There are only two solutions to this issue. The first is to stop deny rights to some people and not to others. The other is to dissolve marriage as a legal institution, taking with it any and all benefits that come with it. In this country either everyone or no one has rights. That is what the founding fathers meant when they said All are created equal.