Better Late Than Never?

Proposition 8 in California has been causing quite a ruckus lately. Many people are surprised that with all my other libertarian ideas that I would be in favor of banning gay marriage so this will be my effort to try and explain it coherently. First and foremost my church is strongly opposed to it and I learned long ago that our Heavenly Father is smarter than me and not to question him.
From a more libertarian perspective I look back to the history of marriage. For thousands of years churches were the ones who kept records of births, marriages, etc. States really didn't care all that much whether a person was married or not. People were married by their church in order to avoid the sin of fornication. Now I think you would have a hard time arguing that gay people are trying to avoid the sin of fornication when they really don't give a crap about the sin of homosexuality. Therefore I think marriage is a religious thing and that the government has no business in even issuing licenses. That is a right of churches that has been taken away to a large degree. Remember we have the freedom of religion not from religion.
The second reason gays would want to be married is to be entitled to the benefits that the government gives to married couples. Libertarians generally view any special interest treatment as bad so this doesn't really apply. Besides they can already get most of the benefits just by becoming a domestic partnership in California I believe.
The third reason gays would want to get married is to make homosexuality more main stream. This is simply an advertising campaign and has nothing to do with their rights (unless they believe they have the right to not be offended like so many others).
I hope this explains it better. If you have any questions or comments or think I am psycho please leave me a comment and I will try to explain it better.