Matt Barber, a "Christian" talk show radio host went on record to say: “Make no question about it: the institution of natural marriage was designed by, and is owned by, the creator of the universe, God,” Barber said. “And we will not render unto Caesar what does not belong to Caesar.”
There are so many points wrong with this statement that it's not even funny:
1) There is no such thing as "natural" marriage. Marriage has always been a legal/political institution, even in tribal cultures where couplings are generally recognized to gain access to resources, for families to join together to collectively gain from each other. Marriage is an institution which has vastly varying degrees of interpretation depending on culture, nationality, and law in each nation. There is no universal "Natural" marriage. It's a legal contract which endows two people with legal obligations to each other, and to the state as a unified social unit.
2) Christ said "Render unto Caesar that which is Caesar's, render unto God, that which is God's" was in response to a question about paying taxes. Taxes are a matter of the state, not of God, and in the broader context, Christ was even taking it a step further and saying don't mix faith and politics. The two are inherently incompatible. Furthermore than that, what you BELIEVE is in the realm of "God" is not shared by the larger society and while marriage may carry some significant spiritual meaning, that meaning cannot be imposed on everybody on the basis that it's faith-based. If marriage has a significant spiritual meaning to you, then exercise that tenant of your faith, but let everyone else do as they please. You do not have the right to impose your religious view of marriage on the larger public. Such an action is highly unethical and defeats the purpose of faith all together. Forced faith is not faith, but oppression, and subjugation, and is anti-Christ to the extreme.
3) Christians have an obligation to follow the laws as they're written in the land to the best of their ability. Please share with my how letting my LGBT brothers and sisters enter into a legally binding civil marriage upsets your world? You are not responsible for the belief of others, you have no right to impose your views on others, and you have no right to judge others. If you insist on doing so, the you have lost the entire point of Christianity in it's entirety and you're in a cult of political personality.