I'm not in touch with them now, but I wonder what our conversations about marriage equality would be like. Many fundamentalists follow the dictum "Love the sinner, hate the sin." They may have immense caring and compassion for gay individuals, but they don't accept same-sex relationships as good. (Others are less scrupulous about loving the sinner, and their entire reaction is tilted toward hate.)
I'm not going to discuss the biblical justifications for being for or against same-sex relationships. These arguments have thoroughly hashed out, so I'm sure everyone is familiar with them. No repetition here is required.
When I think of some fundamentalists I've known, I can't predict which doctrine they would follow--against homosexuality per tradition or accepting of homosexuality in God's loving nature. I've certainly seen some friends torn between the harsh judgments of their religious and the love that is also preached and practiced there.
For example, one coworker and I shared many stories about our faiths and families. We also shared a strong work ethic and a serious, responsible attitude to life, so we built up a lot of mutual respect. She knew that I wasn't a saved Christian and didn't believe in an afterlife. I still remember the tears in her eyes as I departed from that job and from her life as an unsaved soul. Her final wish was that someday I would believe in heaven. Not because I was just another soul that was lost, but because I was someone about whom she cared deeply.
So I won't condemn this kind of Christian for being an anti-gay bigot because in her heart there wasn't bigotry or hatred. That doesn't mean I give this kind of Christian a pass. I have pushed some of my born-again friends very hard on abortion, and even harder on doctrine of eternal damnation.
I want them to question some of the received dogmas of their religion, but in doing so, I'm asking for a lot. In effect, I'm saying "Because I'm someone you respect and like, I want you to question the religions ideals that you've held for decades." What right do I have to do that? Only the right of the free exchange of ideas between people who love and respect one another. So I can't condemn them if they decide to stick to the traditional interpretation of the Bible, because I've learned to love and respect them even though we disagree on some fundamental questions. For anyone who'll take the time to really listen, really think, and most of all, really care, I have immense respect.
I don't expect everyone to feel the same way. I won't tell my gay friends to give these Christians a pass. But regarding the ones I've gotten to know well, maybe I'd explain how I can still be friends with anti-marriage-equality advocates. It's something like 'Love the sinner, hate the sin.' On many days I'm the sinner, or the person who's wrong, so I remember not to hate.