Blow Them Away: How Christians Learned to Love War
How Christians went from refusing to fight to waging war and why it matters?
On October 24, 2001, perhaps the best known evangelical pastor in America sat down in front of a CNN camera and said something remarkable. Jerry Falwell told the anchor that President Bush should "blow them away in the name of the Lord."
Nobody blinked.
Fascinating. Not that Falwell said it. People say outrageous things on television every day. The interesting part was that millions of Christians across America heard a pastor call for holy war and didn't think anything of it.
But I did. And that surprised me.
I am the proud son of a soldier and deacon. Like many American evangelicals, I grew up admiring the military and celebrating its victories. But hearing those words coming from a pastor was unsettling. Something felt off. And I didn't know why.
With a little digging, I came across the words of another pastor named Justin Martyr. He also had strong opinions about war. He wrote them down around the year 138 AD, roughly nineteen centuries before Falwell's CNN appearance: "We who formerly used to murder one another now refrain from even making war upon our enemies."
Same faith. Same Bible. Opposite conclusions.
How does that happen? How does a religion shift from "we no longer make war" to "blow them away"? That is the question I wanted to answer. And what I discovered might shock you.
The First Christians Refused to Fight
Here is something I was not expecting to find. The earliest followers of Jesus were, almost universally, opposed to violence of any kind. Not just to war. To violence.
These were people who lived inside the most militarized empire of their day. Roman soldiers were everywhere. Military victory was the engine of Roman culture, Roman economy, Roman identity. And the Christians living inside that empire looked at all of it and said not us.
The record from the first two centuries is remarkably consistent. Justin Martyr quoted the prophecy from Isaiah about nations no longer lifting the sword and pointed to Christian behavior as living proof it was already being fulfilled.[1] Tatian, writing around 160 AD, declared, "I refuse military office."[2] Athenagoras, in 177 AD, wrote that Christians could not even bear to watch a man being killed, much less participate in killing themselves.[3] Tertullian, one of the most prolific writers of the early Church, argued that Jesus had settled the matter in the Garden of Gethsemane, when he disarmed Peter and, by doing so, "ungirded every soldier."[4] Lactantius, writing in the early fourth century, put it plainly: "It will not be lawful for a just man to engage in warfare."[5]
These were not fringe minority voices. They were the mainstream.
Now, of course there were exceptions. Some Christians did serve in the Roman military. There is evidence that by 173 AD some Christians served in the ranks of what historians call the Thundering Legion under Marcus Aurelius.[6] And the closer a Christian community lived to the dangerous edges of the Empire, where barbarian raids were a real and regular threat, the more likely Christians were to relax their convictions out of sheer necessity. But even then, they were acting against the clear and consistent teaching of their Church: Christians were not to participate in violence of any kind.
Why? Two reasons. First, Roman soldiers were required to offer sacrifices to the Emperor as divine. Christians would not worship idols. Second, and more fundamentally, the shedding of blood was seen as simply incompatible with the life and teachings of Jesus.[7]
Early Christians almost universally refused to engage in or support violence of any kind, whether entertainment and execution in the coliseum or taking up arms on the battlefield.
Then something changed. And it had very little to do with the Bible.
Constantine and the Great Reversal
In 312 AD, a Roman general named Constantine was preparing to fight for control of the Empire at the Milvian Bridge outside Rome. The night before the battle, he claimed to have received a vision. A cross of light appeared in the sky above the sun, bearing the inscription: "Conquer by this."[8]
He won. He gave credit to the Christian God. And everything changed.
Within a generation, Christianity went from a persecuted minority religion to the official faith of the most powerful empire in the world. The Church that had survived centuries of torture and execution now sat at the center of Roman power.
It must have felt like a miracle. And in the intoxication of that moment, almost nobody stopped to ask a very important question: What does it cost a religion to be embraced by an empire?
Historian Alistair Kee puts it plainly. Constantine “came into the Church impulsively on his own terms as the result of a battle. He bypassed all the discipline of the Church. It never occurred to him to question his actions by Christian standards.”[9] And Christians didn't question his actions either. They were too relieved. Too grateful. Too eager to enjoy the protection of a powerful patron after centuries of suffering.
So they adapted.
Eusebius, the Church historian who became one of Constantine's most enthusiastic admirers, began describing the Emperor's military campaigns as holy crusades, as the very work of God against God's enemies.[10] The same Church that had told its people they could not wield a sword was now telling them the Emperor's wars were God's wars.
Nothing in Scripture had changed. Nothing in the teachings of Jesus had changed. What changed was the Church's position in the Empire.
Ambrose: Building the Framework
The first Christian thinker to put forth a formal theory of just war was Ambrose of Milan, who lived from 340 to 397 AD. Ambrose was two things at once: a Roman aristocrat and a Christian bishop. When he sat down to write about war, both showed up.
The Christian tradition Ambrose inherited was almost universally nonviolent. There was no existing Christian theological argument for war he could draw from. So he drew from Roman philosophy instead. He turned to Cicero.
Three centuries before Ambrose, Cicero laid out a careful philosophical framework for ethical war in his work On Duty.[11] Ambrose took that framework, wove in stories from the Old Testament, and presented the whole thing as a Christian theology. He made it feel biblical. But the underlying architecture was Roman philosophy, not Scripture.
What Ambrose built was morally compelling. War, he argued, could not be fought for personal gain or territorial expansion.[12] It had to be a last resort, pursued only after every other option had been exhausted.[13] And it had to aim at peace, not the destruction of the enemy.
Ambrose was rigidly committed to his framework. When the Emperor Theodosius ordered the massacre of thousands of civilians in Thessalonica, Ambrose rebuked him, called it sin, and demanded public repentance.[14] He was not rubber-stamping every violent act of the Empire.
This commitment to his principles is admirable. But his principles did not come from careful reading of the New Testament. They came from Cicero, dressed in Old Testament clothing.
And the early Church's nonviolence? Ambrose said it applied only to clergy. Priests should not fight. Everyone else could, as long as his conditions were met.
Two and a half centuries of Christian consensus began to crumble.
Augustine: The Fountainhead
What Ambrose sketched, Augustine painted in detail.
He lived from 354 to 430 AD, and scholars call him "the fountainhead" of the just war tradition.[15] For the next thousand years, when Christian thinkers wanted to justify war, they quoted Augustine. When they wanted to limit war, they quoted Augustine. He became the authority everyone reached for, on every side of the war conversation. His influence on Christian thinking about war is cannot be overstated.
Augustine's world was falling apart. He watched the once impervious Roman Empire begin to falter. In 410 AD, the Visigoths sacked Rome. It was the first time the city had fallen to an enemy in eight hundred years. The shock was immense. And in the aftermath, a charge began circulating that Christianity had made Rome weak. All that talk of love and turning the other cheek had left the Empire unable to defend itself.
Augustine pushed back. Hard.
War, he argued, under the right conditions, was not only permitted, but it could be an act of love. A soldier who fights to protect the innocent, motivated by duty rather than hatred, is doing something virtuous.[16] What mattered was not the outward act of violence but the inward disposition of the person doing the violence. This was a significant shift. It did not just permit war. It gave war a spiritual logic.
He then formally detailed what Ambrose had only sketched. Just war required three things: a just cause, a legitimate authority, and a right intention — meaning the restoration of peace and justice, not vengeance or conquest.[17]
But Augustine went further than Ambrose had been willing to go. He argued that God himself could authorize war, and that the Church, as God's representative on earth, could sanction the use of force against heretics. He did not just argue this in the abstract. He acted on it, supporting the Emperor's use of force against a Christian sect called the Donatists.[18] The Christians who had once filled the prisons of Rome as martyrs were now, with Augustine's blessing, filling them with their theological opponents.
None of this was driven by fresh discoveries in Scripture. It was driven by political pressure and self-preservation. Augustine needed to defend Christianity against the charge that it had weakened Rome. He needed to secure the Church's place inside imperial power. And he succeeded brilliantly.
Aquinas: Organizing it All
Several centuries after Augustine, a Dominican friar named Thomas Aquinas sat down to organize the just war tradition into something a student could memorize.
For a war to be just, Aquinas wrote, three conditions must be met. First, it must be declared by a legitimate authority. Second, there must be a just cause. Third, those waging it must have a right intention.[19]
Clean. Memorable. And almost entirely borrowed from Augustine, who borrowed it from Ambrose, who borrowed it from Cicero.
Aquinas's contribution was not originality. His teaching on war "is slight and unoriginal. Devised more or less wholesale from Augustine... it is abstract and theoretical, and inspired by no personal emotion or thought."[20] What Aquinas did was repackage the tradition for the medieval university, making it accessible to a new generation of scholars. Making just war thinking easier to understand and communicate made it easier to spread.
What is more interesting is what Aquinas left out. The moral guardrails that Ambrose had insisted on — war as a genuine last resort, war aimed specifically at peace — barely appear in his writings. Why?
By the thirteenth century, the question was no longer whether Christians could go to war. That had been settled. War was woven into the fabric of European society, blessed by the Church, and funded by the pope. The Crusades had been running for two hundred years. Aquinas didn't need to defend war. He just needed to better organize the Christian defense of war.
Society had changed again. Theology followed.
Vitoria: The New World Changes the Question
In the early sixteenth century, Spanish conquistadors were doing something the just war tradition had never encountered before. They were sailing to distant lands, meeting people unknown to them, and killing them. Systematically. In enormous numbers. And doing it, they insisted, in the name of Jesus.
Francisco de Vitoria was watching. And he was horrified.
Vitoria was a Spanish Dominican friar, born around 1480, and he was one of the sharpest theological minds of his generation. What he saw the conquistadors doing in the Americas forced him to ask questions that Ambrose, Augustine, and Aquinas had never needed to, because none of them had ever imagined a world so large.
He started with the most basic question of all: Did the indigenous peoples of the Americas have rights? The conquistadors had assumed the answer was no. Vitoria said yes. They were full human beings with genuine claims to their land, their lives, and their governance.[21] In 1532, that was radical. He went even further. The fact that indigenous peoples were not Christian, he argued, did not justify warring against them. The cause of Christianity alone did not justify violence.[22]
Then Vitoria asked a provocative question: What if both sides in a war genuinely believed they were justified in fighting? The indigenous people defending their land believed they were under attack, because they were. The soldiers arriving on their shores believed they were advancing a righteous cause. Both could be wrong. But if both acted in good faith, their culpability was reduced.[23] In war, Vitoria was saying, it is not always clear who is right and who is wrong.
He also introduced proportionality and the protection of non-combatants as explicit conditions of just war. Gunpowder had arrived. Wars could now destroy entire populations. Someone had to address that, and Vitoria did.
Once again, a change in the world drove a change in Christian theology.
The Tradition Keeps Moving
The just war tradition has never stopped evolving to new political realities, new technologies, and new kinds of conflict. Changes in the world continuously drive changes in Christian ethics.
On September 11, 2001, nineteen men with box cutters changed the shape of modern warfare. The enemy the United States now faced wore no uniforms, claimed no territory, and operated across a dozen national borders simultaneously.
Cicero, Ambrose, Augustine, Aquinas, and Vitoria never imagined this. Christian ethicists worked quickly to apply the old just war criteria to the new situation. Most concluded that the initial military response could be justified. But as America's War on Terror progressed, the more difficult the questions grew and the more contested the answers became.[24]
Then drones arrived. The Obama administration dramatically expanded the use of unmanned aerial vehicles to target and kill suspected terrorists, including in countries with which the United States was not formally at war. Just war theory had always assumed that soldiers bore genuine personal risk and this would limit violence. A soldier on a battlefield has skin in the game. But what happens when the person pulling the trigger is sitting in a climate-controlled trailer in Nevada, piloting a drone over Yemen, and will be home for dinner? Scholars began asking whether the traditional just war criteria even applied anymore.[25]
Then, in January 2020, the Trump administration ordered a drone strike at the Baghdad airport that killed Iranian General Qasem Soleimani. Was it an act of war? A preemptive strike? Legitimate self-defense? Just war scholars, military ethicists, and international lawyers debated it immediately. The answers depended entirely on which version of just war theory you were applying, and how you defined legitimate authority, just cause, and proportionality.[26]
The point is not that any of these decisions were necessarily wrong. The point is more basic than that. Every generation faces new political, technological, and military realities. Every generation stretches the tradition to fit them. This ongoing evolution is driven by pragmatism, pressure, and politics more than prayerful exegesis of Scripture.
An Important Question
A defining mark of evangelicalism is its a commitment to Scripture as divine revelation. "We believe the Bible to be the inspired, the only infallible, authoritative Word of God," we say.[27] For evangelicals, this is the conviction informing all other convictions.
But the just war tradition, as I have traced it here, did not grow out of prayerful examination of Scripture. It grew from Constantine's political needs, from Cicero’s pagan philosophy, from the pressures Augustine felt in a crumbling Empire, from the medieval Church's entanglement with political power, from the inhumane cruelty of the conquistadors, from America’s response to the September 11 attacks, from evolution of technology and the advent of stateless terrorism.
The earliest Christians read the same Bible we have. They reached very different conclusions about war and violence. As the world changed, the Church changed with it.
Which brings me back to where I started. Two pastors. Same faith. Same Bible. Opposite conclusions. I still think about that.
Jerry Falwell's words made me uneasy for a reason I couldn't name at the time. I think I can name it now. It wasn't that he supported the war. It was how presumed and unexamined that support was. How completely untroubled he was — we all were — by how his declaration contradicted the long tradition that had come before him.
The history of just war theory raises an unavoidable question for Christians who believe Scripture is God-breathed and authoritative: How much of what we believe about war and violence actually comes from the Bible? And how much of it is capitulation to the world and timeswe live in, telling us what to think?
NOTES
1. Justin Martyr, First Apology, chap. 39, in The Ante-Nicene Fathers, vol. 1, ed. Alexander Roberts and James Donaldson (Buffalo: Christian Literature Publishing, 1885), 176.
2. Tatian, Address to the Greeks, chap. 11, in The Ante-Nicene Fathers, vol. 2, ed. Alexander Roberts and James Donaldson (Buffalo: Christian Literature Publishing, 1885), 69.
3. Athenagoras, A Plea for the Christians, chap. 35, in The Ante-Nicene Fathers, vol. 2, ed. Alexander Roberts and James Donaldson (Buffalo: Christian Literature Publishing, 1885), 146.
4. Tertullian, On Idolatry, chap. 19, in The Ante-Nicene Fathers, vol. 3, ed. Alexander Roberts and James Donaldson (Buffalo: Christian Literature Publishing, 1885), 73.
5. Lactantius, The Divine Institutes, bk. 5, chap. 20, in The Ante-Nicene Fathers, vol. 7, ed. Alexander Roberts and James Donaldson (Buffalo: Christian Literature Publishing, 1886), 169.
6. Roland H. Bainton, Christian Attitudes Toward War and Peace: A Historical Survey and Critical Re-evaluation (Nashville: Abingdon Press, 1960), 68. The account is preserved in Tertullian, Apology, chap. 5, and Eusebius of Caesarea, Ecclesiastical History, bk. 5, chap. 5.
7. G. I. A. D. Draper, "The Origins of the Just War Tradition," New Blackfriars 46, no. 533 (November 1964): 84.
8. Eusebius of Caesarea, Life of Constantine, bk. 1, chap. 28, trans. Ernest Cushing Richardson, in Nicene and Post-Nicene Fathers, Second Series, vol. 1, ed. Philip Schaff and Henry Wace (Buffalo: Christian Literature Publishing, 1890), 490.
9. Alistair Kee, Constantine versus Christ: The Triumph of Ideology (London: SCM Press, 1982), 17.
10. Eusebius of Caesarea, Life of Constantine, bk. 1, chap. 3, in Nicene and Post-Nicene Fathers, Second Series, vol. 1, 483.
11. Cicero, On Duties, bk. 1, para. 34, ed. M. T. Griffin and E. M. Atkins (Cambridge: Cambridge University Press, 1991), 14.
12. Ambrose of Milan, On the Duties of the Clergy, bk. 1, chap. 28, paras. 137-138, in Nicene and Post-Nicene Fathers, Second Series, vol. 10, ed. Philip Schaff and Henry Wace (Buffalo: Christian Literature Publishing, 1896), 26.
13. Ambrose of Milan, On the Duties of the Clergy, bk. 1, chap. 35, para. 177, in Nicene and Post-Nicene Fathers, Second Series, vol. 10, 35.
14. Ambrose of Milan, Letters, letter 51, paras. 3-7, in Nicene and Post-Nicene Fathers, Second Series, vol. 10, 450-451.
15. Robert A. Markus, "Saint Augustine's Views on the 'Just War,'" in The Church and War, ed. W. J. Sheils, Studies in Church History 20 (Oxford: Blackwell, 1983), 1.
16. Augustine of Hippo, Letters, letter 189, para. 6, in Nicene and Post-Nicene Fathers, First Series, vol. 1, ed. Philip Schaff (Buffalo: Christian Literature Publishing, 1886), 554.
17. Augustine of Hippo, Against Faustus the Manichean, bk. 22, chap. 74, in Nicene and Post-Nicene Fathers, First Series, vol. 4, ed. Philip Schaff (Buffalo: Christian Literature Publishing, 1887), 301.
18. Markus, "Saint Augustine's Views on the 'Just War,'" 9.
19. Thomas Aquinas, Summa Theologica, II-II, q. 40, art. 1, trans. Fathers of the English Dominican Province (New York: Benziger Brothers, 1947).
20. Joan D. Tooke, The Just War in Aquinas and Grotius (London: SPCK, 1965), 170.
21. Francis de Vitoria, De Indis, in Political Writings, ed. Anthony Pagden and Jeremy Lawrance (Cambridge: Cambridge University Press, 1991), 250-251.
22. Ibid., 271.
23. Ibid., 315.
24. Jean Bethke Elshtain, Just War against Terror: The Burden of American Power in a Violent World (New York: Basic Books, 2003), 57-75.
25. Bradley Jay Strawser, "Moral Predators: The Duty to Employ Uninhabited Aerial Vehicles," Journal of Military Ethics 9, no. 4 (2010): 342-368.
26. Michael Walzer, Just and Unjust Wars: A Moral Argument with Historical Illustrations, 5th ed. (New York: Basic Books, 2015), chaps. 4-6.
27. https://www.nae.org/statement-of-faith/
