As the case of Odinism suggests, Nature abhors a vacuum. If, as the world grows richer and more educated, supernatural religion continues to decline, then the void of belief may be filled by new creeds. Revived paganism is likely to be limited in its appeal. More successful will be secular creeds that combine the imagery of modern science and technology with the certainty and zeal of pre-modern faiths. Marxism was justified by a pseudoscience of history, while pseudoscientific Social Darwinism provided the underpinnings of German National Socialism. Communists and Nazis alike believed that they were scientific and up-to-date, even as they enjoyed the kind of certainty and solidarity that religion traditionally has provided.

The advanced industrial nations of North America, Europe and East Asia suffer from Muslim jihadism, but they are not going to be conquered from without or within by champions of a new caliphate. The real threat to post-Christian civilization will come from within. Like Marxism and National Socialism, it will take the form of a militant secular creed, but adopt the trappings and rhetoric of science and technology and appeal to educated people whose spiritual longings go unmet. The adherents of the next major religion to sweep through the secular West will insist that it is science and will deny that it is a religion at all.