Just War: How Scripture Shapes Conceptions of War and Peace

1. Introduction

We live in a broken world. We are broken by sin individually and collectively. As Christians, we know this brokenness is not final. In no way does the pain and agony of sin on this earth have an eternal grip on us. But in the midst of this hope that we experience through Christ, we interact daily with the pains and evil currently present on earth. We know these pains will not subside until the Lord returns, so we must face them head-on. One of the most painful phenomena humans encounter is warfare. It is the largest, most destructive form of human conflict and can span from small-scale conflict between local tribes to world-threatening campaigns between nuclear powers. War is a reality we all face.

​ Despite the pain of war, is it always a zero-sum game that ends negatively? Are there ways to conduct war that are just? Does Scripture point us to how we conduct ourselves before, during, and after war? These are questions that many Christians wrestle with today, and they are the same questions Augustine wrestled with in the 4th century when he developed the beginnings of what would later be known as Just War Theory. While Augustine’s full theology of war spans many texts, this essay focuses on a single text, his Letter to Faustus, as an illuminating example of scriptural reasoning about warfare. What we can see in America’s current foreign policy is that, as Augustine remarks, war is permissible when undertaken to protect an innocent party from an evil party, through means necessary only to stop that perpetration, and only when the final goal of the war is peace.¹

​ In this paper, I will address the following: how the themes of the imago dei and the Fall explain why war exists, why the principles of the Just War Theory remain applicable today, which key Scriptures inform our view of war, and finally, an example of how the principles presented in scripture applied to a decision of the United States government to go to war in defense of our nation. War, if justified, may offer a way to treat people as image-bearers by protecting them from aggressors.

2. Made in the Image of God and the Fall: Why War Happens

Two main themes throughout the arc of scripture show why violence, conflict, and war exist in our world today: the imago dei and the Fall. Genesis 1:26-27 says, “Then God said, ‘Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.’ So God created mankind in his own image, in the image of God he created them; male and female he created them.” The idea of humanity being made in the image of God is critical to understanding the sanctity of life. God did not create humanity only to be the dominant species on earth; He created us to reflect His character. When humanity was created, God looked at what he had made and said, “it was very good” (Genesis 1:31). The bestowing of the imago onto humanity demonstrates his love for humanity. The Creator’s work is perfect. We were created to reflect the character and love of the Creator who made us, yet we would fail in our purpose.

​ As the serpent tested Eve’s obedience to the Lord’s commands and deceived her into eating the forbidden fruit, along with Adam following, sin entered the world. Genesis 3:7 says “the eyes of both of them” were opened to their nakedness–to their disobedience. Cast from the garden, Adam and Eve’s family experiences immense strife as their son Cain kills his brother Abel in Genesis 4:8 out of jealousy and anger. This murder is our first glimpse into the origins of the war we see today. Just as one man killed his brother out of jealousy and anger, so too do nations and non-state actors conduct violence. These actions are taken because they do not recognize the inherent worth of people bestowed by their Creator. They neglect the principle of the imago dei. What are we to do in this situation? Do we stand by and watch, or do we take action?

3. Principles of Just War Theory

In order to understand just war reasoning, consider the following remarks from Augustine in his Letter to Faustus:

What is the evil of war? Is it the death of some who will soon die in any case, that others may live in peaceful subjection? This is merely cowardly dislike, not any religious feeling.  The real evils in war are love of violence, revengeful cruelty, fierce and implacable enmity, wild resistance, and the lust of power, and such like; and it is generally to punish these things, when force is required to inflict the punishment, that, in obedience to God or some lawful authorities, good men undertake wars, when they find themselves in such a position as regards the conduct of human affairs, that right conduct requires them to act, or to make others act, in this way.²

Moreover,

A great deal depends on the causes for which men undertake wars, and on the authority they have for doing so; for the natural order which seeks the peace of mankind, ordains that the monarch should have the power of undertaking war if he thinks it advisable, and that the soldiers should perform their military duties in behalf of the peace and safety of the community.  When war is undertaken in obedience to God, who would rebuke, or humble, or crush the pride of man, it must be allowed to be righteous war; for even the wars which arise from human passion cannot harm the eternal well-being of God, nor even the saints.³

In his Letter to Faustus, Augustine supports this reasoning of just war with several moral principles. First, war must be taken when it is in obedience to God to demolish the pride of man: “When war is undertaken in obedience to God, who would rebuke, or humble, or crush the pride of man, it must be allowed to be righteous war….”⁴ What we see from this text is that a war can only be justified when it is in obedience to God and addresses a fundamental flaw in the human spirit, such as pride. Now, although this is seldom the sole reason for a conflict, when a decision is made to go to war, the leader must understand that it cannot solely be for their gain, but it must punish a wrong. This first principle can also be seen as defending the indefensible, and, by doing so, it crushes the opponent consumed with the pride of man.

Second, the only legitimate goal of war is peace. “A great deal depends on the causes for which men undertake wars, and on the authority they have for doing so; for the natural order which seeks the peace of mankind.”⁵ Although this may seem like a simple principle, it is difficult to keep at the front of mind throughout a war. Wars are long and often drawn out. A war conducted in a just manner must continuously seek peace and take every opportunity to secure it. This does not mean entering peacetime that will clearly return to conflict. It means to earnestly seek a peaceful end at every step of the conflict. This is difficult to evaluate due to the nature of the principle. The principle is based on self-reflection by decision-makers and therefore is unlikely to be properly evaluated by the public. Despite the difficulty of evaluation, the principle is strong as it ensures that peace is the ultimate goal, not strife. 

Lastly, when war is conducted unjustly and corrupted by the same evils it seeks to address, it will be ineffective and should be considered unjust. “The real evils in war are love of violence, revengeful cruelty, fierce and implacable enmity, wild resistance, and the lust of power, and such like; and it is generally to punish these things, when force is required to inflict the punishment.”⁶ Although wars are inherently violent and reflect the sins of our world, the corruption of a force seeking peace will culminate in the opposite of the initial intended result. This principle poses difficulties when confronting the realities of violence and the enemy on the battlefield, but it must be held at a macro level. The leaders of a war must not perpetrate the same acts they intend to stop.

4. Key Scriptures to Consider when Analyzing a Just War

Scripture must always be the starting point of practical reasoning, and Augustine’s perspective on when war is justified, as seen by his response to Faustus, uses Scripture as its basis and framework. Romans 13:1-4 says, “Let everyone be subject to the governing authorities, for there is no authority except that which God has established.” In this verse, we see the sovereignty of Christ. God is the ultimate authority as the sovereign leader over all the earth, so human leaders cannot truly hold authority without God’s establishment. The passage then goes on to say “the authorities that exist have been established by God.” Although this can be difficult for us to reconcile given the evil leaders we have seen throughout history, it is still true. Despite how it feels, the truth remains. That passage continues:

“Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves. For rulers hold no terror for those who do right, but for those who do wrong. Do you want to be free from fear of the one in authority? Then do what is right and you will be commended. For the one in authority is God’s servant for your good. But if you do wrong, be afraid, for rulers do not bear the sword for no reason. They are God’s servants, agents of wrath to bring punishment on the wrongdoer,” (Romans 13:2-4)

In this passage, Paul shows that those in authority are called to do what is right. Leaders are called to serve the people, not to be served. This is where tyrannical leaders go wrong. Their power is wielded to serve themselves. In verse four we see that Paul warns those who do wrong. These wrongdoers are reminded that rulers “do not bear the sword for no reason.” And this is where we apply the reasoning modeled by Augustine in his Letter to Faustus. It is in this moment that a clear wrong, as defined by Scripture, can be addressed through force. God has given rulers the means to apply force. This passage of Scripture even states that these rulers are God’s servants to bring “punishment on the wrongdoer.” This sounds like too much power for one person to hold, but the distinction we must make is that it is not humans who are determining what is right and wrong; it is God. 

Scripture offers us a moral code to follow, and the decision of when to move forward with an act of war must be made by recognizing true evil, properly addressing it, and seeking peace as the ultimate end. In 1 Peter 2, we see this call on authority to follow God’s authorities on earth who have been sent by him: “Submit yourselves for the Lord’s sake to every human authority: whether to the emperor, as the supreme authority, or to governors, who are sent by him to punish those who do wrong and to commend those who do right.” Scripture places a high call on rulers and authorities because they have been given the “sword”: the power to wage war, the power to defend life through the taking of it. God does not condone evil. Instead, he calls leaders to pursue peace and good, which is why these passages do not rest on human power, but on the power of God.

5. Case Study: Applying Just War Theory to the War on Terror

In recent history, the War on Terror clearly exemplifies why a country would wage war on an enemy due to an existential threat and evil (a just cause), yet also face immense difficulty in carrying out its mission while upholding moral standards. In the aftermath of the Al-Qaeda terrorist attacks on 9/11, the United States waged war on terror in Afghanistan, the hub of Al-Qaeda, and this war would spread throughout the Middle East and to the rest of the world. This war continues today as the United States combats terror groups in Iraq, Iran, Syria, Somalia, Western Africa, and many other places across the globe.

The 2001 Authorization of the Use of Military Force, passed by the United States Congress, gave the US military the power to “use all necessary and appropriate force against those nations, organizations, or persons he [The President of the United States] determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons.”⁷ This was the start of what many would consider a just war. The principles of why and how it was waged largely reflect those we see in scripture and in Augustine’s perspectives of justified war.

First, as previously stated, war must be undertaken only when it is in obedience to God to redress the pride of man. War can also be waged in defense of an indefensible group. Belligerent groups like Al-Qaeda and its affiliates represent the epitome of human pride. Their contempt for the West and “lust of power” led them to commit acts of terror in the name of religious struggle.  The United States wages war against terror to rebuff this pride and defend those made vulnerable by their attacks.

Secondly, wars must seek the final result of peace. Eradication of terror and the installation of peace is the goal of a War on Terror. The only way to achieve peace in this circumstance is through war; no negotiation with the perpetrators is possible. The United States is still fighting the war on terror and affiliates of Al-Qaeda are still active throughout the world.

Lastly, when war is conducted unjustly and corrupted by the same evils it seeks to address, it will be ineffective and should be considered unjust.  Throughout the War on Terror, the United States faced (and continues to face) evil acts displaying the full corruption of the heart. The U.S. uses force to address these evils and mitigate them, but that does not mean the United States is faultless. There have been times when the military’s actions have been improper or indiscriminate, and do not demonstrate adequate adherence to just war principles. This is when we have to face the realities of a sinful world, trying to uphold a fully just cause–it is impossible. But that does not mean that all other actions are worthless. It means that we must seek to hold that standard.

6. Conclusion

War is complex. A decision to go to war should be based on the distinction between good and evil. The difficulty America faces is that we are flawed. Rulers are sinful. We as a country cannot make a perfectly just decision because we cannot be without flaws. But the United States should not seek to enter into war with our adversaries. We should do so when it is necessary. We must consider why we see it as a just action. These principles of Just War have been heavily present in US reasoning regarding conflict, and these principles are largely based on scripture. Whether our country recognizes it or not, we often make decisions based on the truths of scripture. We are flawed and cannot do so perfectly. Despite these flaws, when policymakers base their policy on moral principles, they are basing it on scriptural truths because God is the ultimate source of moral reasoning. 

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¹ Augustine, Reply to Faustus the Manichaean, XXII.
² Augustine, Reply to Faustus the Manichaean, trans., Richard Stothert and edited by Philip Schaff (Buffalo: Christian Literature Publishing Co., 1887XXII. Chapter 74.
³ Ibid.
⁴ Augustine, Reply to Faustus the Manichaean, XXII. Chapter 75.
⁵ Ibid.
⁶ Ibid., XXII, 74.
⁷Authorization for Use of Military Force, Pub. L. 107-40, 115 Stat. 224, 2001.