I used to think that it shouldn't be legalized. I'm a Christian. But I've changed over the years, especially as the political fight got bitter and brutal.
Even though I agree the Bible labels any sexual acts outside a married relationship between a man and a woman as sexual immorality/sin, I eventually agreed that this should have NO bearing on the legal rights of a human to do as they wish. Even if the Christian God thinks it's immoral, separation of church and state means that gay couples should have the legal, political right to do it because it has important ramifications on their lives that they are lacking without the right to marry.
As a Christian, I actually wish my fellow believers would have let people do as they wish and stopped fighting so hard against this cause. It did nothing but embitter gays and non-Christians against the gospel, cause hatred and bickering, and divide our nation. That is not what Jesus would have wanted us to do. He would have wanted us to be straightforward and truthful about what the Word of God says, but we are in NO position to police people on spiritual/moral matters!! Jesus never did that. He spoke boldly but manipulated/controlled no one, especially legally/politically!
If you are not a Christian, and you don't have the Holy Spirit within you, you don't profess to follow God's commands, then the Bible means nothing to you, so why do my brothers try to beat people over the head with it? I wouldn't want a Jew or Muslim to force me what I can and cannot eat because I do not ascribe to their set of moral standards. Similarly, non-Christians don't ascribe to our standards, and as long as what gays are doing doesn't infringe on my American freedoms or hurt me or society, then I shouldn't stand in their way.
I believe that the struggle on religious people's side against gay people has only hurt the gospel. Which I believe dishonors God.
In conclusion, I don't mind what happened on Friday. To confuse all of you even more, I identify as bisexual (though mostly gay).
My greatest hope is that legal gay marriage being decided will remove one awful obstacle in between discussions of the gospel, and hopefully Christians can get back to figuring out how to love and embrace the LGBTQ community instead of fighting bitterly to keep them from legal rights they should have in this country.