As Douthat sees it, the Church of America also promotes the heresy of nationalism, confusing the mission of the gospel with the mission of the United States. At home, this heresy is championed by religious liberals, who mistake the kingdom of heaven for their visions of a "great society", having anointed Barack Obama as its latest high priest. For their part, many evangelicals and "theocons" became unduly enamoured of George Bush's democracy agenda in the Muslim world, as if free elections and the US military could usher in the political equivalent of the Second Coming of Christ.

These heresies are not new, but the decline of traditional belief has given them a ferocious influence over our culture and our politics. Only biblical religion can resist the hubris of nationalism, Douthat argues, because every party, every political agenda and every nation stands under the judgment of Almighty God. Likewise, only the weighty virtues of the ancient faith — such as humility and charity — have any power to curb self-absorption and consumerism in all their varied forms (including by-products of runaway capitalism).

In Douthat's skilful critique, even the disillusioned doubter is given reasons to hope for the renewal of Christian orthodoxy. "There is something to be said for returning to the source," he writes, "for looking again at your half-forgotten patrimony, for considering anew the possibility that Christianity might be an inheritance rather than a burden." Amen to that.