You mean the constitution that govt can't take money at gunpoint to fund another guy's religion? Actually, I think that's pretty neat.
As I'm sure you know, that doesn't prohibit states from establishing religions, as they had state religions when the country was founded/the Constitution written. Also, putting up a Christmas tree is not congress passing a law establishing a federal religion. It does cause some to run in circles shrieking in horror, though.
Regarding your paying taxes by gun point. Yes, taxes are terrible but we have to fund the government somehow. I would hope that no one on FR wants a large government. Do you prefer no government at all?
I'm sorry that the Constitution is so disturbing to you.