So, that being said I really don't think the state has any business attempting to control marriage period. To me marriage is an oath between a man and a woman and God. Outside the Judeo-Christian world I don't see that marriage has any particular merit. So if atheists or gays want to have some sort of ceremony and call it a marriage then so be it. I don't think the state should be involved in my marriage or theirs.
In the same vein, gays have been pledging themselves to one another in commitment ceremonies for decades now. They stand in front of their friends, family, and community and pledge to honor and love one another. This is the same as your vision of christian marriage.
The problem is that there are legal benefits to marriage. For example, without being married a family can make death bed decisions without involving that person's partner. A gay partner can actually be banned from even entering a hospital room if the family decides to. When gay partners break up there is no recourse to recoup shared investments. There is difficulty in getting insurance and medical benefits if there isn't a marriage certificate. These are the things that gay couples are seeking.
The OTHER side of that coin however is that the state should not force me as a Christian to be involved with something that I consider an abomination.
Then you shouldn't run a business that requires you to do things that you consider an abomination.
When you open a business that is open to the public you have made a pledge to society that you are not going to discriminate. If you can't keep that pledge, then you shouldn't be in that business.
You say the Colorado baker still has the right to go to church. His rights do not end at the church house doors.
His religious rights do not extend to discriminating as part of a public business. If that were the case, then people would have never had to take these signs down.
As long as his religious practice doesn't harm someone else.
Being denied services at businesses is harmful as determined by the courts.
and by harm I mean physically harm, not "emotionally upset".
So what is the physical harm that comes to a baker when they bake a cake for a gay wedding?
Basically the government doesn't belong in the pastry shop or the bedroom.
Tell that to the health inspector, USDA, OSHA, labor office, IRS, etc.
Obviously, public businesses are regulated by the government, and the government has every right to regulate businesses.