Some quick thoughts:
The decline of America is often (and rightly) compared to that of the decline of the Roman Empire.
This is looked at as a bad thing. However, what happened as a result of this cultural meltdown? The Empire submitted itself to Christianity and Christian culture flourished.
There is much to be excited about in building Christian civilization, if the church would 1) think that it’s possible, 2) think that it should do so, and 3) get busy preparing.