It's not that religious establishments are above the law, it's that congress (the source of laws) does not have the authority to make any laws that apply to religious establishments.
It's a subtle difference. Churchgoers don't get a free pass to break the law. The establishment simply is immune to regulation of any kind attempted to be placed upon the organization itself by congress.
> congress (the source of laws) does not have the authority to make any laws that apply to religious establishments
It's not obvious that this is what was meant by 1st amendment. Other interpretation is that congress simply can't make laws that apply exclusively to religious establishments.
EDIT: I must add that the interpretation you mentioned is undoubtedly the "canonical" one in public's mind, so the situation is unlikely to change soon.
If you studied the topic, then surely you're very familiar with what's written in the Wikipedia article on the Establishment Clause [0], which makes it very clear that its purpose is to prevent the government from establishing a state religion (including by favoring one religion over another), not to prevent it from making any laws that can affect religious institutions.
Let´s say I had a religion that had a "Thou shalt sacrifice a non-believer being every Wednesday to appease Xantako the Moon God" clause.
Are you arguing that my congregation should be immune from any restrictions being placed on us for worshipping our god by slowly killing everyone around us who does not share our view , because we operate outside of the law ?
The parent explicitly pointed out that religious organizations don't operate outside the law. If they did, literally every corporation and political party in the US would also establish itself as a religion.
What Congress isn't allowed to do is pass a law stating "no religious organizations in the US are allowed to practice human sacrifice." But you still wouldn't be able to appease Xanakto the Moon God because Congress is still allowed to make murder illegal in general, just not exclusively in the context of religious practice.
But not paying taxes on your income is illegal "in general". So one could interpret that as "all organisations should pay taxes if they have income"...
As I understand it, religious organizations have tax exempt status as non-profits under laws which also include educational and scientific institutions.
And, ironically, the reason religious organizations are included at all is the belief that taxing them would provide a means by which governments could interfere with religion in violation of the First Amendment.
It's a subtle difference. Churchgoers don't get a free pass to break the law. The establishment simply is immune to regulation of any kind attempted to be placed upon the organization itself by congress.