What do you mean post-Christian?

Joshua at RazorsKiss is amazed that many Christians in the United States still think we live in a "Christian culture":

Our country, and our culture, are in the grip of subjectivism, humanism, and a rebellion against all convention. We are NOT in the grip of the Holiness and Majesty of the Lord God, Omnipotent. We are in the grip of a worldview which says “live all you can, cause you just live once… you have the right to do whatever you want” - to quote a DC Talk song from a ways back.

The solution, Joshua aptly notes, is not trying to change the culture, but first changing ourselves--to be transformed into the image of Christ.