After reading about the bakery in Oregon that is being sued for refusing service to a gay couple, I have one thing to say. This bakery has the same rights that the couple has, and that includes the right to honor their beliefs. I realize there are antidiscrimination laws, but they are not seeking something life-altering like a job or a residence. It's a cake. I'm sure the couple considers themselves mature adults, and part of being a mature adult is accepting that you will not always get your own way.
There must be other bakeries that would be happy to work with them. I suggest they contact one of those bakeries and leave this bakery alone.