I mean, judges in developed countries make these kind of judgement calls all the time, probably dozens of times a year in a country the size of the US. There's

I mean, judges in developed countries make these kind of judgement calls all the time, probably dozens of times a year in a country the size of the US. There's tons of well-developed common law around what is a legitimate expression of religion, what isn't, etc. Easily over 30 Supreme Court cases on this over the last couple of centuries. If I assert that I have a religious exemption to stop signs, taxes, gun laws, anti-discrimination laws, securities laws, etc. etc. judges can & do 'decide [what] your religion is', as you put it. Unless you assert that literally zero laws apply to the religious, there's just no way around judges actually making these decisions