Is War or Violence Ever Acceptable?
Jesus said blessed are the peacemakers, told his followers to love their enemies, and told Peter to put his sword away. He also said he came not to bring peace but a sword. Holding these together honestly is harder than choosing one and ignoring the other.
The Answer
Christianity has the most complicated relationship with violence of any major religion. On one hand: the founder was a pacifist who told his disciples to love their enemies, turn the other cheek, and put their swords away. On the other hand: within three hundred years of his death, Christians were running an empire and conducting wars of conquest.
This is not hypocrisy — or not only hypocrisy. It is the result of taking seriously the question of what a tradition committed to peace does when people are being massacred and only violence seems to stop it.
Jesus's own teaching is not as simply pacifist as it is sometimes presented:
He told his disciples to "turn the other cheek" (Matthew 5:39) — but the original context is about personal insults and honor disputes, not military assault. He said "put your sword back in its place" to Peter (Matthew 26:52) — but he also said, moments earlier, "if you don't have a sword, sell your cloak and buy one" (Luke 22:36). He said "blessed are the peacemakers" (Matthew 5:9) — but also "I did not come to bring peace, but a sword" (Matthew 10:34), meaning the division that comes from moral clarity rather than comfortable compromise.
He drove merchants from the Temple with a whip he made himself (John 2:15). He called the Pharisees "whitewashed tombs" and "broods of vipers." He was not a passive, conflict-avoiding figure. He was confrontational, provocative, and ultimately died because he was too threatening to the established order to be tolerated.
What he consistently rejected was vengeance, retaliatory violence for personal honor, and the glorification of military power as a religious virtue. These are distinct from the question of whether defensive violence to protect the innocent can ever be morally justified.
The honest answer is that serious Jewish and Christian thinkers have disagreed about this for centuries — and the disagreement is not resolved by proof-texting. What both traditions agree on is that violence, when it occurs, must meet a high moral threshold, must be a last resort, must be directed at combatants rather than civilians, and must aim at a just and durable peace rather than victory for its own sake.
The Jewish Reformer's Lens
The Hebrew Bible contains extensive warfare — the conquest of Canaan, the wars of the kings, the battles described in the historical books. It also contains the prophetic vision of universal disarmament: "They shall beat their swords into plowshares and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore" (Isaiah 2:4, Micah 4:3).
The Talmud developed rules of warfare that were, for their time, remarkably protective of civilians. Before attacking a city, the Israelites were required to offer terms of peace. Non-combatants were to be protected. Fruit-bearing trees were not to be destroyed during siege (Deuteronomy 20:19 — the law of bal tashchit, not destroying what sustains life, applied even in war). The death of innocents, even in justified warfare, was a moral tragedy to be minimized, not celebrated.
The Talmud also contains a remarkable passage (Sanhedrin 72a) establishing the principle of rodef (pursuer) — the obligation to use force, including lethal force if necessary, to stop someone who is actively trying to kill an innocent person. This is not aggression. It is a specific, limited permission to use defensive force to protect life.
Modern Jewish thought on war ranges from classical pacifism (represented by some strands of liberal Judaism) to just war theory to more nationalist perspectives. What the tradition consistently rejects is war for economic expansion, religious conquest, or national glory. What it consistently permits — and may require — is defense of life.
The Holocaust profoundly shaped modern Jewish thinking about pacifism. The historical experience of a people who trusted in civilization's protections and were systematically murdered despite — or because of — their powerlessness created a strong Jewish argument for the moral necessity of self-defense capabilities. This is not a betrayal of prophetic ethics. It is their application to a world that demonstrated its worst possibilities.
Catholic Social Teaching
The Catholic Church developed just war theory — a framework for determining when, if ever, the use of military force is morally permissible — beginning with Augustine (4th century) and developed further by Thomas Aquinas (13th century). The framework requires that all of the following conditions be met simultaneously:
- Just cause — the harm being prevented must be real and serious (defense against attack, protection of the innocent from grave harm)
- Legitimate authority — declared by appropriate governmental authority, not private actors
- Right intention — the goal must be peace and justice, not conquest, revenge, or economic gain
- Last resort — all peaceful alternatives must have been genuinely exhausted
- Reasonable chance of success — not futile
- Proportionality — the damage inflicted must not be greater than the good achieved
- Discrimination — combatants and civilians must be distinguished; intentionally targeting civilians is always prohibited
Just war theory is a serious moral framework that makes war harder to justify, not easier. In practice, most wars fail several of these criteria. The Catechism (§2309) notes that "the evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good" — but also warns repeatedly that war's horrors make the bar for justification extremely high.
Pope John Paul II (who lived through Nazi occupation of Poland) spoke of "an absolute limit that cannot be crossed" in the use of violence, even in defense. Pope Francis has argued that in the age of weapons of mass destruction, just war theory may need to be revisited entirely — that the concept of a "just war" may no longer be coherent when the weapons available can produce civilian casualties on industrial scales.
The Church also maintains a legitimate place for conscientious objection — the refusal to participate in war on moral or religious grounds. The Catechism (§2311) says: "Public authorities should make equitable provision for those who for reasons of conscience refuse to bear arms."
Sources & Citations
- Matthew 5:9, 38–48 — Beatitudes and Love of Enemies (New Testament) One of the four Gospels, Sermon on the Mount. "Blessed are the peacemakers, for they will be called children of God." Then: "Do not resist an evil person. If anyone slaps you on the right cheek, turn to them the other cheek also." And: "Love your enemies and pray for those who persecute you." These are among the most demanding ethical teachings in human history. The "turn the other cheek" instruction in context describes a backhanded slap — an insult of social status — not military assault. The principle of nonretaliatory response to personal dishonor does not settle the question of defensive warfare, but it sets a clear direction.
- Matthew 26:52 vs. Luke 22:36 — Sword passages (New Testament) Two passages in the Gospels that appear to be in tension. In Luke 22:36, in the hours before his arrest, Jesus tells his disciples to arm themselves with swords if they don't have them. In Matthew 26:52, when Peter uses a sword to defend him, Jesus tells Peter to put it away: "All who draw the sword will die by the sword." Most interpreters read the Luke passage as Jesus testing his disciples' understanding — not a literal instruction — and the Matthew passage as the definitive teaching.
- Isaiah 2:4 — Swords into Plowshares (Hebrew Bible) One of the Major Prophets. The prophetic vision of universal disarmament and peace — quoted on the wall of the United Nations building in New York. The vision is not conditional on the other side disarming first. It is a directional commitment: this is where the world is meant to go. Both Israel and the Church have used this vision as the ultimate standard by which all military arrangements are judged and found provisional.
- Catechism of the Catholic Church, §§2302–2317 The official compendium of Catholic teaching. These sections cover the just war tradition in full: the conditions for legitimate defense, the criteria for just war, the prohibition on attacking civilians, and the right to conscientious objection. The Catechism also covers the requirement to work for the "avoidance of war" through "the fostering of international institutions and the prevention of conflicts by improving relations among nations."
- Talmud Bavli, Sanhedrin 72a — The Law of the Pursuer (Rodef) The Babylonian Talmud. Establishes the *rodef* principle: one who is actively pursuing an innocent person to kill them may themselves be stopped by lethal force if necessary to save the innocent life. This is a careful, limited exception to the general prohibition on taking human life — defensive, not aggressive, and explicitly limited to active threat situations. It represents the Jewish tradition's serious engagement with hard cases, not a blanket endorsement of violence.
- Pope Francis, Address to Conference on "Nonviolence and Just Peace" (2016) Pope Francis addressed an international conference convened by Pax Christi International and other Catholic organizations calling for a reexamination of just war theory in light of modern weapons capabilities and the demonstrated failure of military solutions to produce lasting peace. Francis endorsed the conference's final document, which called for a new "theology of peace" and renewed commitment to nonviolence as a first resort rather than a last resort.
What Should We Do?
For everyone: The teaching of Jesus does not permit the glorification of war, the celebration of killing, or the treatment of military power as a religious virtue. Militarism — the cultural elevation of military force as the primary means of solving problems — is not a Christian virtue, whatever the political conventions of some religious communities suggest.
Practically, this means: support diplomatic institutions, international law, and negotiated conflict resolution — not because they always work, but because they are attempts to address conflict without mass death. Support veterans who deal with moral injury — the psychological damage that comes from participating in violence, even justified violence. War produces trauma in its participants, not only its victims.
If you believe a particular military action is just, apply all seven criteria of just war theory honestly — including proportionality and discrimination. "We had to respond" does not meet the standard unless the response was proportionate and targeted. "But they started it" is not a moral argument.
For Catholics specifically: The Church's tradition of conscientious objection is real and significant. Catholics who serve in the military are not guaranteed that every order they receive will meet the moral standards of just war theory. The tradition permits — and in some cases requires — refusal to participate in actions that clearly violate those standards. This is not disloyalty or cowardice. It is the tradition working as intended.
The Church also maintains a network of peace-building organizations — Pax Christi International, the Sant'Egidio Community, and others — that do active mediation work in conflict zones. These are the institutional expression of "blessed are the peacemakers." Engage with and support them.