American jurisprudence is based on the idea that our rights are God given, regardless of anyone's personal interpretation of God. This is the foundation of our rights and liberties, that they are not given by a government but are inherent to our nature. Without this principle, rights become something that man gives and takes from others.
The separation of church and state does not extend beyond the restrictions against state sponsored or enforced religion. That the state is not to force or restrict religious freedom does not erase the faith-based foundation of our country and laws, and does not change the fundamental concept of God given rights. Hell, if it helps any, Washington, Jefferson and others weren't actually Christian, from what I understand Freemasons call their God 'Adonai' or some such, and Jefferson copy-pasted his own bible to make it read how he wanted it to. These weren't the lampoonish stereotype Bible-thumpers that usually come to mind when talking about separation of church and state. None the less, they saw that by defining our rights as inherent in our creation (or inherent to our evolution, if that suites you) they could possibly set up a government by and for the people, instead of the power structures of all previous governments. But like Adams said (posted here in this sub) this only works in a moral and religious society.
Whether you believe in God, Adonai, Yahweh, The Prime Mover, Krishna, whatever, doesn't really matter, what's important about the Biblical foundations of America is that without our rights being sacred and God-given, then we effectively have no rights. Rights become something the government gives and takes as it pleases.

Do you believe that life and rights are sacred? Or just ideas?