The way I see it, our commitment for each other and being together was an expression of our love in and of itself. He gave up his entire life to move thousands of miles away from anywhere he'd ever known to be with me -- the only greater expression of love I can think of is that he's still here and not going anywhere.
When we got married, we really didn't see that as just an expression of love, we already had ways to express it to each other daily, and frankly those expressions are no one else's concern than ours. We paid for the marriage license and got married so that I could be on his health insurance, so that we could file jointly for taxes, and so that we would have legal rights to speak for each other in the event of severe illness or injury. Maybe not as romantic as most people's view of marriage, and I know a lot of people still don't see it this way, but that's the way I've always seen it.
I agree that it is our God-given right to love each other, but unfortunately it is in the capacity of the government to decide who can and cannot be legally married. We can express our love in many ways that the government never gets a piece of, but it won't help a lot with insurance.