"A Secular Faith"

Darryl Hart's new book, "A Secular Faith:  Why Christianity Favors the Separation of Church and State," has been attracting some attention.  Certainly, I agree that Christianity favors the "separation of Church and State," properly understood.  It sounds like, though (see this review), Hart understands "separation" fairly broadly.  That is, he contends not only that Christians should favor the independence of the Church from the State (i.e., the Freedom of the Church), but also that Christianity is "essentially a spiritual and eternal faith, one occupied with a world to come rather than the passing and temporal affairs of this world," one that "has very little to say about politics or the ordering of society."  Still, the book sounds like it is worth checking out.