Might want to look at this: http://en.wikipedia.org/wiki/Secularity
The views in that article or so sick and perverse it's difficult to comprehend how any rational person can hold them to be true. In statements like "we still live in a civilization that was nurtured and shaped by Christianity" and "The moral language of Western civilization is uniquely Christian", the author is using historical euphemisms. Saying Western civilization was "nurtured and shaped" by Christianity fails to acknowledge that Christianity raped and pillaged
the cultures of others. Declaring that the "moral language of Western civilization is uniquely Christian" doesn't acknowledge that "Christians" co-opted the rituals and stories of other religions (both Christmas and Easter were pagan holidays), and worked to wipe-out the cultures and traditions of native peoples around the world - from kidnapping children of aborigines in Australia to be raised in Christian homes, to torturing Native peoples of Central America for practicing their own religious traditions. THAT is the legacy of Christianity. All societies around the world had develop standards for how one should treat their neighbor and how a community "should organize and govern itself". They didn't need for Christianity to be IMPOSED on them.
It's outrageous that people try to continue to blame "godlessness" for all the ills of society yet fail to acknowledge the evils done in the name of God and Christianity. This is especially true for those living in the United States. To this day we live in occupied lands taken from conquered native peoples and founded in large part through the enslavement of men, women and children stolen from foreign lands. So THIS is a "Christian" nation? This is a nation "of God"?