In my opinion religion should not influence any political or legal decisions directly. In the worst case of this we end up with things like Sharia Law (which I find abominable) that allow execution for things like homosexuality, conversion to another religion or sex outside of marriage - none of these things have any strong logical reason to be illegal. In lesser cases you end up with things like a ban on gay marriage which once again clearly comes from a religious point of view.
Edit: Also I agree with whoever said that 'In God We Trust' should remain on money and stuff, at least for now. However 'under God' should be removed from the pledge of allegience - partly because it was only added 50 years ago and partly because nobody should have to say a pledge in which they don't believe.
