you know, i'm a fairly religious christian, actually, and i heard a priest say something interesting about gay marriage once: he said, that if in this day and age, same sex couples are going to live together for years and years, and try and support each other through illness, raise children, pay taxes, and so on, then they NEED marriage - they need the ethical and religious bonds of the institution of marriage. he meant that in the religious sense, but i also think it applies legally. if you're going to object to gay marriage, legally, then you're saying that gay couples don't need the same legal protections that straight couples do. why? don't they get sick? don't they get pregnant?
gays are people too. people are equal. equal people, equal rights. so let gays marry, just like you. BECAUSE you're a christian - or just because you're an american!