John Adams said we are a nations of laws and not of men.
He was responding to enlightenment intellectuals by going all the way back to Aristotle who said that "it is more proper that the law should govern rather than man."
Our Consitution presuposes self-evident truths and the laws of nature and nature's God.
It is only the Natural Law of God that gives us the freedom to avoid the consequences of sin - my sin and yours.
For more see this link: http://media.1170kfaq.com/audio/piper0111131.mp3