What sort of person votes to deny basic rights to other people? Whom does it harm when same-sex couples marry? Even if your religion says homosexuality is a sin (to believe that you have to believe it's a choice, which, like evolution and climate-change denial is to ignore all the scientific evidence), why choose to harm those who believe differently? I'd never vote to ban shrimp cocktails or sacred underpants.
Actually to cast a vote, purposefully, to discriminate against people who pose no threat and who are just as human as you are -- such a thing requires a particular sort of self-righteous ignorance, and the ability to pretend that it's neither hateful nor damaging to innocent people. Whatever casting such a vote is, it is most certainly not Christ-like. It is neither loving of your fellow man, charitable, nor treating others as you'd be treated yourself. What it is is some kind of smug self-satisfaction, a kind of "take that, you people whom I neither know or understand, nor care to look in the eye while I'm doing this. I need to believe I'm better than you, and since I have no real evidence, at least I can do this, and pretend."
There's an initiative on the ballot in my state to overturn our recent law allowing same-sex marriage. Signatures to validate it were higher in number than on any previous initiative, which bodes ill. That I live in a state, a country, where so many people can vote to hurt fellow citizens who represent no threat to them is more than depressing. It's shameful. How can any decent person do it? How can they sleep at night? How can they muster the will to make their mark in such a heartless and harmful way? In the name of a religion so many of whose other teachings they choose to ignore. It's horrifying, it really is.