Same if a baker bakes wedding cakes and sell them to anyone regardless of race, religion, or national origin - but refuses to sell to gay customers. Is not the cake the baker won't produce, it's the customer. In that case (as we've seen from the Oregon law and court rulings) then the baker is in violation of the law.
Example #1: A Jewish baker has a nazi walk in, plain clothes, no identifying features on his person that he's a nazi. The nazi asks the Jew to bake him a yellow cake with chocolate frosting; maybe some sprinkles on top and a rose or something. The Jew bakes him the cake and nobody is the wiser.
Example #2: A Jewish baker has a nazi walk in, wearing a swastika armband and asks the Jew to make him a cake with a swastika emblem frosted on top with the caption "Happy Nazi-Pride Day!". The Jew refuses, as is his right. The nazi here is inviting the Jew to be party to celebrating something the Jew is loathe to do from deep personal convictions. Even when the Jew isn't citing his religious objections; because in the Torah, there's nothing stated about "you must not associate with nazis under pain of eternal damnation". Yet nobody but the nazis would contest the Jew was in his rights to refuse.
Example #1a: A Christian baker has a gay man walk in his shop, plain clothes, no identifying features on his person that he is gay. Even if he did identify he was gay, it wouldn't matter because to a Christian, it's "hate the sin, not the sinner". The gay asks the Christian to bake him a cake, strawberry, with vanilla icing. Maybe some chocolate chips on top with some irises frosted. The Christian bakes him the cake without violating his faith.
Example #2a: A Christian baker has two gay men walk in his shop, hanging all over each other, snuggling and kissing on the mouth. They ask the Christian baker to bake them a
wedding cake that says "Happy Marriage,
Adam & Steve". The Christian refuses, as is his right. The homosexuals here are inviting the Christian to be party to celebrating something the Christian is loathe to do from deep personal convictions. Yet there is something mentioned directly in the Bible about facilitating
the spread of homosexuality as a cultural value; under pain of eternal damnation of the Christian's soul. His passive refusal is his right because this is no longer about an individual homosexual; it's about promoting homosexuality as a new cultural value: which is
strictly forbidden by the New Testament of Jesus Christ in Jude 1.
Since both nazism and homosexuality are behaviors; ideologies peculiar to certain people signing up, the decision by the 7th circuit court of appeals finding that sexual-orientation is not covered under the 1964 Civil Rights Act is important here. So I don't want to hear any comparisons about "what if a black person walked into a store and they refused because their belief is that black people suck"...or whatever. Race is covered under the Act. Same if it was a woman. Same if it was a man.
And, if a gay baker wanted to refuse to bake a cake for a Christian celebration; it would be his right as well. If his deepest beliefs are "Christianity is an affront to my personal beliefs!", he'd be in his right to refuse. He'd go broke of course. But that is his choice to make.