It was supposed to be the war to end all wars. After the armistice on the 11th hour of the 11th day of the 11th month (100 years ago Sunday on November 11, 1918), it would be known as the Great War. No one would have thought to call it World War I, because they could not fathom the even greater horrors to come just a few decades later in World War II. The peace of 1918 would not hold.

Americans pay far closer attention to World War II, even though the country suffered more than 117,000 military deaths in two brief and bloody years from 1917 to 1918. Indeed, the Meuse-Argonne Offensive that ended 100 years ago Sunday was by far the deadliest battle in American history, surpassing both the Battle of the Bulge and also the Normandy Invasion in World War II. Neither America, nor any other antagonists that suffered even greater losses, would ever be the same after this terrible and utterly avoidable conflict.

Philip Jenkins, distinguished professor of history for the Institute for Studies of Religion at Baylor University, has written an excellent book on the religious dimensions to this “holy war.” And we corresponded on the occasion of this somber anniversary to consider how the war shaped global Christianity, religious fervor, Christian theology, peace movements, and more. You can also listen to my earlier interview with Jenkins, “How World War I Became a Religious Crusade.

Did peace in Europe shape Western or even global Christianity in any lasting ways? 

Well, if not the peace, the war absolutely did have such an impact, and particularly the events of 1918.

The war destroyed ancient centers of Christianity in the Middle East, especially among the Armenians and Assyrians. At the same time, the suspension of missionary enterprises shifted the balance in Africa and Asia to native forms of faith. That movement was massively enhanced in 1918 by the influenza epidemic, which killed between 50 million and 100 million worldwide. That event showed the utter inability of Western missionaries and medics, and drove many ordinary people to seek help from healing churches, and from individual prophets and charismatic leaders. The great age of the African Independent Churches dates from this time.

As to the West, I can hardly begin! Contrary to myth, the war did not destroy the faith of ordinary people, but it did drive thought and writing by theologians, above all by Karl Barth. Barth published the first edition of his commentary on Romans in 1919, but it was the second edition, published in 1922, that according to one Catholic observer, “burst like a bombshell on the playground of the European theologians.” The book was a frontal attack on the liberal conventions that had shaped mainstream theology since the Enlightenment.

And that does not begin to talk about the great Catholic thinkers like Henri de Lubac, whose war experiences shaped their lives, and we see their lasting influence transforming the church in the Vatican Council of the 1960s.

Dare I say that the Christian world we know today is the product of 1918?

How did Christian pastors help their congregations cope with the aftermath of the deadliest conflict the world had ever known? Did their reactions vary between victor and vanquished, or even within countries on the same side?

Your question about the diversity of responses is spot-on, but I would focus on one absolutely common theme that we might not think of so centrally today. Obviously priests and pastors had to help returning veterans, especially in a time of social and economic chaos, and open revolution in some countries. But what they had in common was that they all concentrated on the work of commemoration, which occupied so much effort over the next decade or so. That meant designing and building monuments of various kinds—monuments that are richly informative of popular religious interpretations of the war, with all their angels and knights. It also meant commemorative services and rituals, ensuring that the dead would always be remembered. That enterprise shaped for instance the scriptural readings used, and also the hymns. Those activities became a major part of what churches did for many years, and they helped bind ordinary believers to state churches where they existed. Often, too, the pastors and priests themselves had seen front-line services, many of them as chaplains.

That whole work of remembrance is a big reason why we don’t see mass secularization after 1918, contrary to popular myth. 

You single out the Germans as being particularly zealous in claiming God’s favor on their war effort. Did they repent or at least revise and rethink their views in light of their country’s defeat? 

I certainly do not want to attach blame to any country for being uniquely bloodthirsty, though I would make a case that German political leaders (as opposed to ordinary people) should take much of the blame for the war itself. And they received the powerful support of the country’s religious leaders, especially in the Protestant churches. Far from repenting, most of those clerical leaders played a crucial role in developing the sinister “stab in the back” mythology, which provided such ammunition for the Nazis. One of Germany’s legendary Protestant preachers, Bruno Doehring, was a pioneering advocate of these ideas. As he said as early as 1918, God had not abandoned his people, rather our Volk had abandoned him, as sinister elites “treacherously desecrated the altar of the fatherland.” Although he did not single out Jews for blame, other Rightists would soon do so: The Jews stabbed Germany in the back!

The famous Lutheran theologian Reinhold Seeberg composed an epitaph for a war monument that is at once a perfect example of Latin at its most precise and concise, and a chilling manifesto for the generation of 1940. Seeberg addressed the graduates of the University of Berlin killed in the war as Invictis Victi Victuri—to the unconquered, from the conquered, who will themselves conquer.

And here is a bizarre note: Seeberg’s most famous theological pupil and disciple was Dietrich Bonhoeffer, the legendary anti-Nazi martyr.

Could the Second World War have been prevented by a different plan for peace in 1918?

When people ask this question, the normal answer is to regret the harsh terms inflicted on Germany. For many reasons, I would disagree. What went wrong in 1918 is that the Allies permitted the German forces to end the war in a way that allowed them to pretend that this was an agreed peace, rather than an outright surrender by armed forces on the verge of total collapse. It also meant that Germany avoided actual combat on its territory, which would have brought home the lesson that they were really defeated and crushed, like in 1945. That allowed German leaders to cook up the “stab in the back” mythology, the whole lie about betrayal.

Much of America’s self-identity stems from the Second World War. But how did peace leave America a different nation from the one that entered the war on the Allied side in 1917? Did that self-identity carry any particular religious overtones?

The war was not so much a new departure, but a continuation of trends that had been much in evidence since the start of the century—roughly, the Progressive Era. These are not directly caused by the war or the peace, but the war provided a critical focus for ideas already in the atmosphere.

Several points come to mind. White Protestants saw the moral crusade of the war as a pivotal moment to impose their ideology on the nation, which especially took the form of Prohibition, and all that meant for sexual ideology and moral purity. Prohibition was justified by the war effort, and it is a 1917 measure, although it does not begin until 1919. Women’s suffrage was part of the same ideological package, which was of course a wonderful example of social progress. The bad side is that it was often linked to an ugly kind of nativism and anti-immigrant sentiment. Not coincidentally, the Ku Klux Klan revival followed in the early 1920s.

The other great religious effect was in the form of millenarian and apocalyptic ideas, following such events as the British capture of Jerusalem in 1917, and the Balfour Declaration promising the establishment of a Jewish state in Palestine. That made the 1920s a great era for apocalyptic and fundamentalist thought.

What did peace mean for Christians living in the original homeland for Christianity? And what about in Russia?

Between about 1915 and 1930, we are dealing with perhaps the greatest age of martyrdom and mass killing of Christians in history. That includes perhaps 1.5 million Armenians murdered, not to mention mass slaughter by the Bolsheviks in Russia.

That all had two key consequences. One was the creation of Middle East that was more clearly Islamic, with far smaller Christian minorities.

It also ended the long-familiar tripartite division of Christianity into the worlds of Catholic, Protestant, and Orthodox. Although Orthodox believers and thinkers obviously survived, their influence and impact collapsed with the loss of Russia. For the first time, people began to think of Christianity as bipolar—Protestant and Catholic.

When did the world begin to see this war as an avoidable mistake? Does that shift tell us anything about changing attitudes toward religion?

That happens in different degrees in different countries. Despite what we may think from something like All Quiet on the Western Front, most Germans never regretted the fact of war, but they really regretted losing it. The great shift in Western countries happened in the early 1930s, with the growth of pacifist and leftist sentiment.

From a religious point of view, the most important single work was Ray Abrams’s 1933 book Preachers Present Arms, a minor classic of American religious history. The book tries to describe how American clergy (especially mainliners) became such fire-breathing advocates of a literal holy war or crusade against Germany. Abrams himself was writing at a time when the antiwar reaction had set in with a vengeance, and he is incredulous that so many educated believers could have fallen for the view that the Great War was in any sense just. He saw the massive shift to pro-war sentiment as a naïve concession to cynical manipulation by Allied agents, in association with militarist forces within the U.S. government. For Abrams, American clergy gave way to “propagandism” and media-incited panic in a kind of mass hysteria reminiscent of the colonial-era witch hunts.

Abrams’s book had a vast influence on later religious thought, certainly through the Vietnam years.