I suspect that it will eventually get pushed to the Supreme Court for an opinion of the constitutionality of denying the right to marry to a group based on sexual discrimination. The court will have no choice but to say that it can not be denied to one group while being granted to another. At that point all states will be forced to allow it.
Because it is a state sanctified civil contract with deep roots in civil law the argument of religiosity goes out the door.
So one way or another it will spread to all of the states eventually.
I'm atheist so none of the bible quotes mean anything to me and I have nothing against it.