As I said, you don't get to determine the religious obligations of others.
No, but I can call them hypocrites if that is what their behavior indicates. And religious obligation? Show me where in the bible it says not to bake a cake for a couple you don't agree with. Show me an example where Jesus, the person every single Christian no matter the domination is striving to be like, would see this as acceptable behavior. Go ahead.
Religious obligations should not impose upon another person. Which is exactly what this did. If they were genuine, they would uphold the Biblical Standards for all their customers. That is religious obligation from a Christian (in general) standpoint, is it not?
I would say this no matter the religious justification. If they refused a biracial couple on the grounds that they do not believe in biracial marriages, which is a thing in certain sects, I would be rather interested to see the response from people defending them. (Not you specifically, just in general.) Because that is what they look like to us young whippersnappers.
Speaking of tantrums and stamping one's feet.
Yes, how dare I point out, hyperbolically (is that a word? Ehh, whatever) that refusing to serve a customer in retail, for anything less than said customer disturbing the peace or being abusive, is childish behavior. Come on, you know that you leave your opinions at the door when you step into work. Owner or not. A customer's life is none of the server's business. At all. Now if they wanted him to write on the cake that gay marriages are the work of God or something, maybe I could be more sympathetic to his plight. The way I see it now though, he's just being a homophobic bigot and hiding behind his religion like a coward. Simply because of a line located conveniently somewhere in the Bible.
And if they were owners they could decide to not provide porcine products. Inconvenienced by someone's religious obligations in their own store? "Harden the 'F' up".
Well it's called opening a Butcher that does not sell pork. We have those. I forget what they're called. So already they have made a conceited effort not to inconvenience customers shopping there. Because they have made it clear to the public that they don't sell certain products. Like you don't got to a Kosher Butcher and expect a non Kosher thing. (Sorry not particularly versed in Kosher anything.) Did this shop make it clear they do not serve certain types of people? No? Well then that's their fault.
Besides unlike said specialty Butchers, a cake shop bakes cakes, not straight cakes, not gay cakes. Cakes. The ingredients are all the same, the results are all the same, the products are all the same. The intent is the only thing that is different and that has nothing whatsoever to do with selling the products in the first place. I highly doubt many grocery chains, for example, would approve of kids taking certain grocery products and using them to make drugs. They could even have religious objections. We can even suspect such behavior, I mean people with such intentions are not always hard to spot. So then are they participating in the manufacturing of drugs if their customers do so? What of their immortal souls?