It is also prohibited form passing any laws that prohibt free exercise of speech. However, no right is absolute in and of itself. There is no right to yell Fire in a crowded theater, regardless of who might think it would prohibit their freedom of speech. And what is to prevent one form inventing a religion and saying that certain actions are part of said religion? Human sacrifice used to be part of many religions, yet that cannot take place today. You cannot do whatever you want and say your religion tells you to do so.
No, you can't.
However, our Founding Fathers were quite explicit (as were the rulings of our first Supreme Courts) that Man's Laws, absent the Laws of the Christian God found in the Bible, were completely useless to guide a civilized society, or to promulgate a truly free republic.
America was founded as a Christian Nation, and the rights enumerated in our Constitution are acknowledged as coming not from Man, but from God our Creator.
Would you actually try to sell the snake-oil that we can call upon God's Word (and our Founding Fathers' genius) for our inalienable rights out of one side of our mouths, and then deny God's place in either Law or Government with the other side?
That would be two-faced and hypocritical... like a Liberal. ;-/