1. Most religions consider homosexuality a sin. 100% of all world religions, including the major ones in this country, consider homosexuality unacceptable. It is offensive and a swipe to the religious freedom of the majority to have to recognize a relationship they consider sinful. The legal system in the United States evolved out of the laws contained in the Bible. We shouldn't go even farther to tear down those laws.
2. It would weaken the definition and respect for the institution of marriage. The 50 percent divorce rate has already weakened the definition of marriage. In fact, less than 5% of all gays have marriages that last more than 3 years. We shouldn't be taking further steps to define what marriage is. A law allowing gay marriage would increase the number of joke or non-serious marriages, such as a couple of friends who want to save on taxes. Marriage is the most sacred institution in this country, and every society considers it the joining of a man and a woman. It makes biological sense since only a man and woman can pro-create.
3. It would further weaken the traditional family values essential to our society. The building blocks of our society and the thing that makes it strong is the traditional family of man, woman, and children. 100% of all legal marriages being homosexual is what has sustained us through two world wars, terrorist attacks, a Great Depression, and numerous other challenges over the centuries. While friends & lovers come and go, your family is always there. The main reason our culture and values have started to crumble is the weakening of families. Introducing another form of "family" would only make the situation worse.
4. It could provide a slippery slope in the legality of marriage (e.g. having multiple wives or marrying an animal could be next). Gay rights activists claim that these marriages should be allowed because it doesn't hurt anyone, but it could start a chain reaction that destroys the whole idea of marriage. If someone wants to marry his dog, why shouldn't he be able to? What if someone wants to marry their brother or parent? What if someone wants to marry their blow-up doll or have 10 wives? Unless we develop some firm definition of what a marriage is, the options are endless. If these options sound absurd, remember that all it takes is a few activist judges to use the statute to open the door. It doesn't matter if 95 percent of the population disagrees with the policy, one judge can interpret the case the way he or she wants and use the doctrine of stare decisis to impose a law on everyone. Do you remember how two judges in California recently declared the Pledge of Allegiance unconstitutional? If the decision hadn't been overturned, it would have prevented millions of children from being able to say the pledge every morning, despite the fact that 95+ percent of Americans disagreed with the decision.
5. It confuses children about gender roles and expectations of society, and only a man & woman can pro-create. Children learn about expectations and gender roles from a society where 99.5 out of every 100 couples are heterosexual. It's difficult to teach the importance and traditions of the family when such confusion is thrust upon them. Only a man and woman can bear children, and for thousands of years, a man & woman headed household has carried generations of people through life.
6. The gay lifestyle is not something to be encouraged, as a lot of research shows it leads to a much lower life expectancy, psychological disorders, and other problems. Studies show that nearly 50% of living homosexuals, for a variety of reasons, will only live for 30 more years. Just like a lifestyle of smoking, drinking, etc., unhealthy lifestyles should be discouraged.