http://www.atheists.org/ 

Atheism is a doctrine that states that nothing exists but natural phenomena (matter), that thought is a property or function of matter, and that death irreversibly and totally terminates individual organic units. This definition means that there are no forces, phenomena, or entities which exist outside of or apart from physical nature, or which transcend nature, or are “super” natural, nor can there be. Humankind is on its own.

Men determine what is sacred. The atheist does not say, out of hand, nothing is sacred. In fact, I would assert that The Bill of Rights, in particular, the three commandments of religion therein, have sacred status among informed Americans who value freedom above all.