If you want to not serve people who have divorced unbiblically... I see no reason why you can't not serve those people.
I thought those arguing in favor of homosexual marriage bring up that there are financial benefits TO getting married?
Anyways, the main point is this: maybe there are discrepencies (I agree, there are) and problems with the way people are refused service (refuse service to open homosexuals, not refuse service to college students who openly sleep around, or whatever). Ok, so we've established inconsistencies. So that means that, since the beliefs are inconsistent, or perhaps more generally, just don't make sense to someone else ... that you can simply say that those beliefs are therefore invalid and that individual can be forced to violate them?
Not forced to not violate other people's rights, but forced to violate your own beliefs. Forced, yes, to do something as simple as bake a cake for someone, take pictures at their wedding... or more non-simple things like officiate the wedding.
It wouldn't happen, but I can't imagine a minister of the Flying Spaghetti Monster thingy would particularly want to be forced to give Christian vows in a Christian ceremony to a Christian couple because somehow, the Christian couple has a "right" to THAT PERSON offciating their wedding. Because, you know, I have a right to make you do what I want you to do, even if you think it is wrong for you to do it?
Let's say I'm holding a pro-bombing rally. Let's say it's a pro-bomb-the-abortion-clinics rally (obviously, it's not explicitly that). And I want you to provide a meal for us. Should you be forced to do that, and not be able to say "No, I don't want to support bombing abortion clinics. I'm not going to provide food."
I'm a Christian, and I think someone should be able to refuse me service because you think my views are harmful. I don't think the government should be allowed to... but that's a different story... and yes, I do support separating legal and religious "marriage" things... i.e., you want to have a civil union for the legal benefits, fine. Pastors do religious ceremonies. Civil servants to civil ceremonies. I would view myself as "married" even if my state and/or country didn't think I was.