We don't even have to get into the freedom of religion.
Donnachaidh wrote:What tyranny? How does allowing same sex couple to marry change anything for anyone else?
As far as your baker goes, they would have been treated the same way under the law if they had refused to make a special cake for an interracial couple or a Jewish couple or a Mexican couple. Any of those would have violated Title II of the Civil Rights Act of 1964. The fact that they were willing to sell non-special cakes is immaterial to the fact that they refused to perform the service they chose to commercialize on the basis of the customer's sexual orientation. If the baker had not created special cakes for anyone, then refusing to make one for that couple would have been legally acceptable but they chose to create special cakes for others so refusing is not legal.
Freedom of Religion does not mean you get to impose your faith on others, that baker doesn't seem to understand that; if you'd like a more recent example, Kim Davis and her supporters don't either.