Yet the sense in which Western civilization can be described as a "Christian civilization" is neither superficial nor trivial. There is a middle ground between the extremes of viewing Western civilization of merely co-opting Christianity to serve as a thin veneer over an essentially pagan essence and viewing Western civilization as the Kingdom of God on earth.
Western civilization is Christian, or rather, was Christian, in the sense in which it felt guilty for failing to live up to the moral standards of the Bible and this is neither trivial nor superficial. It is perhaps the deepest and most important way in which a civilization can be Christian in the present age between the first and second comings of Christ.
But now, Western civilization is crumbling because it has lost its collective faith. We see this process, named by sociologists as "secularization" and by political philosophers as "liberalism," beginning in the French Revolution at the end of the 18th century on the continent, delayed for a century by the Evangelical Awakening in Britain and America in the 18th century but coming to fruition in the 20th century in Europe and after the 1960s in North America.
Western civilization has no other religious-philosophical worldview or set of first principles to draw upon. The Enlightenment was a reaction against Christian metaphysics, epistemology and ethics and the embrace of the idea of equality as the sine qua non of morality. This idea of equality, combined with a romantic philosophical anthropology and a Utopian eschatology, led 19th century Marxists and 20th century Neo-Marxists to attack the Christian foundations of the West in the name of the new religion of Humanity.
The question of what is to come after Christianity remains murky. Surely they are correct who argue that post-Christian paganism will be extremely different from pre-Christian paganism because the former will have embedded within itself fragments of Christianity. Post-Christian paganism will have a conversionist zeal, a method of purification and redemption and a moralistic sternness that did not characterize the old, tired, paganism supplanted by Christianity in the first millennium of Western civilization.
We see a picture of what this post-Christian paganism looks like in the Nazi, Fascist and Communist movements of the 20th century. Liberalism degenerates into the will to power and the excrescences of religiosity left over after the death of orthodox Christian Faith degenerate into a bloodthirsty, neopagan, religious fanaticism.
I view W. B. Yeats' poem, The Second Coming, published in 1921, as prophetic.
Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
Surely some revelation is at hand;
Surely the Second Coming is at hand.
The Second Coming! Hardly are those words out
When a vast image out of Spiritus Mundi
Troubles my sight: a waste of desert sand;
A shape with lion body and the head of a man,
A gaze blank and pitiless as the sun,
Is moving its slow thighs, while all about it
Wind shadows of the indignant desert birds.
The darkness drops again but now I know
That twenty centuries of stony sleep
Were vexed to nightmare by a rocking cradle,
And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?
The first 8 lines describe the anarchy, out-of-control violence and irrationality of the Great War. The "best" who lack all conviction are the secularized children of believers in Christ who believe in nothing more than liberal tolerance. The "worst" who are full of passionate intensity are those who are inflamed by nationalistic or simply bloodthirsty passions. We can see such people in charge by looking back to the French Revolution or forward to the rise of the Third Reich.
The next 8 lines look to the future; if Christian civilization died in the trenches of the Great War, what will replace it? No civilization can endure long without a soul; something must fill the void. A Second Coming must occur, but if Christian Faith is dead there can be no question of the return of the Lord Jesus Christ on the clouds of heaven in power and glory. That is precisely the Faith which has died. So whatever is to come must be an expression of the Spirit of the Age, which is antithetical to authentic Christian Faith.
The last 4 lines describe a new birth in Bethlehem, suggesting the founding event of a new religion that replaces the old, dead Christian Faith. What is born must incarnate the Spirit of the Age and therefore can be described as a "rough beast." It slouches toward Bethlehem to be born even now, but it has not been born yet. Out of the political, economic, religious, philosophical, ethical and military chaos - in short, civilizational chaos - of 1914-18 will emerge the "New Thing" that will replace, Christianity, the "Old Thing."
What happened in Nazi Germany is the logical expression of the decadence, madness and evil that fills a body whose soul has died. Old, Christian, Western civilization rose up one last time and spent nearly its last ounce of strength slaying the "rough beast" in World War II, but could only do so by making an alliance with another beast, which was nearly as bad. While the West could be said to have won the Cold War against Communism in a superficial, external sense, the tragic reality is that the Spirit of the Age - clothing itself in the ideal of Equality - has entered the Western bloodstream and infected it fatally.
Western civilization - Modernity - is dying. Europe is just playing out the string, while the United States fights for its life against the same infection that felled Europe. What comes next is difficult to describe because it is not a rational, logical, worldview like Christianity, but rather, the antitheses of such a worldview. It is the will to power with a clear conscience that is struggling to be born.
This all sounds extremely pessimistic and it is. But if one asks "Is there any hope?" the answer is always "Yes." But hope can only be found in that which the West has already rejected. Christianity is the only hope for the survival of Western civilization. We must not rule out the possibility of revival and rebirth because we are not fatalists or determinists. God's Providence is unpredictable and surprises may yet await us - especially in the United States where Christianity remains a living community of Faith.
But the rough beast slouching toward Bethlehem to be born - whether it is called the Spirit of the Age, the Antichrist, the Will to Power or Neopaganism - has clearly been born and is fighting for control of Western civilization. Its nihilistic, romantic, Utopian, anarchistic lust for blood and the destruction of the social order is dangerous and demonic. Christians will have to resist it by being willing embrace martyrdom. Revival will entail war.