Well, religion is an option, a personal choice. Christianity is one of the most predominant religions in the world today, meaning that a lot of people prefer that option. It is the general Christian population's belief that being homosexual is a choice, and is a sin. (I don't mean to say that all Christians think this way, but there is a dominant part of the religion's followers that do.) For homosexuals to be able to marry and hold the same rights that a straight person holds when marrying, it comes down to the majority opinion of the state. For instance, Minnesota, Delaware, New York, and Rhode Island all have state legislation that legally allows same sex couples to marry. That legislation was voted into effect by the state populations, males and females over the age of eighteen. So if a state is predominantly anti gay, unless the courts will overrule (as they did in Alabama), the opinion of the population literally can stop people from having equal rights. States like Texas and North Dakota are going to be resistant to changes like this until the government makes a federal law.