The 1st Amendment doesn't extend to activities that are not inherently religious in nature?
No, it does not.
Since always. Go read some case law. Go read Scalia's decision in Smith. There is more than a century of case law that clearly establishes this. As the Supreme Court has explained, first amendment rights are not absolute, the founding fathers never intended religious belief to be a carte blanche by which any and all behavior would be tolerated or protected, the first amendment only applies to behaviors are are of an explicitly religious nature such as going to church, participating in services, praying, believing a certain way, etc, first amendment rights do not protect all actions, particularly when those activities are not distinctly religious activities......and so much more. Go read some case law. Go. Because you clearly haven't a clue. We've been over this before, of course. You keep insisting on ignoring the overwhelming plethora of case law that stands behind me.