You can't wake up one day and say 'I'm for gay marriage ' and wake up the next day and say 'I'm against it.' Wake up one day and say 'I'm pro-choice ' and the next day wake up and say 'I'm pro-life.' There's no credibility there.
I believe in a religion that believes in freedom. Any time I have to accept a religion that won't let me fight a battle for my people I say to hell with that religion.