Originally Posted by listopencil
It goes to the first amendment. Jefferson referred to it in his famous letter. As a society we have to allow "the Church" to operate without interference from "the State", and "the State" must not be influenced by "the Church." Things like performing religious ceremonies, choices about who does and does not get ordained or financial decisions involving member donations are off limits to "the State."
But, by that very same token, "the Church" isn't allowed to carry it's doctrine or its dogma out into the secular world. They aren't allowed to compel others to change their behavior. Religious beliefs are not allowed to be written into law. Of course we can vote against SSM. If we want to vote it down because we think it's an abomination before God we are free to do so. It doesn't matter why we vote the way we do in the eyes of the law. The problem is that the law has to stand on its own merit. Their must be a legitimate reason for that law to exist other than "God said so" or it will be, and should be, struck down.
Can the state force a restaurant owned by a Jew to serve pork or withdraw from the restaurant business? What about the cafeteria of a Jewish school?
Religious practitioners don't just practice their religions on Sunday when they sit in the pew at church or when they're a functionary of the church organization. They practice their religion 24/7/365. The line between secular activities and religious practice isn't nearly as clear as you say it is.