Categories: Military Military Ethics Moral Injury

Thou Shalt Not Kill?

Killing in war takes a huge psychological, moral, and spiritual cost to the human who does so and witnesses it. For American or western service members in particular where the greatest majority of religious faith is that of the Judeo/Christian faith tradition, it is imperative then to understand the basics of this worldview in terms of warfighting and the appropriate bounds of killing another human being.

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"Courage is really fear that's said it's prayers," says Father Vincent J Inghilterra, a top Army Colonel and Catholic priest who has been a military chaplain for 34 years...Talking to these [chaplains], one is struck by their moral realism, and how starkly it contrasts with the effete sentimentality you find among so many clergymen today. Theirs is a sterner faith, a more manlier piety than mainstream America is accustomed to...clerical pacifism leaves many soldiers angry, confused, betrayed, and even spiteful toward faith…”These pronouncements tend to reinforce the notion that religion is for wimps, for prissy-pants, for frilly-suited morons-and those are among the gentler statements I hear," says Chaplain [Eric Verhulst]" It frustrates me, because I know that notion is false, but all I can do is provide a counter-example." (Quotes are taken from LtCol David Grossman’s book, “On Combat”)

Killing in war takes a huge psychological, moral, and spiritual cost to the human who does so and witnesses it. To avoid moral injury and come back whole, warriors must come to grips with what they are doing is justified legally, ethically, and morally so they can return home with peace about it. When considering this, a major moral framework for this discussion among western countries comes from the Judeo/Christian religious worldview. This worldview has been codified in philosophical terms under the name of "Just War Doctrine" or Jus in Bello and Jus post-Bellum. It was started by theologians Augustine of Hippo and Thomas Aquinas. For American service members in particular where the greatest majority of religious faith is that of the Judeo/Christian faith tradition, it is imperative then to understand the basics of this worldview in terms of warfighting and the appropriate bounds of killing another human being to ensure that they execute their warfighting duties unhesitatingly to save theirs and their fellow service members life when it is “kill or be killed” on the battlefield.

Many people when thinking about the morality of killing from a Judeo/Christian worldview typically go to the civil law that the first established national leader of the Jewish nation, a man by the name of Moses, presented to his people written down in multiple books in what is today known as the Old Testament of the Bible. In particular, he laid out a foundational moral code with what has been commonly known as the "10 Commandments". The 6th one has been espoused in the English language often as "Thou Shalt Not Kill." A closer look at the language though which was originally in Hebrew provides a different word than just killing in general and states instead “retzach” which translates to unlawful killing or premeditated murder. This is crucial to understand because when looking at the context of the entire Mosaic Law, killing was sanctioned and even obligatory based on justice needing to be meted out for civil crimes or in the context of the national defense of the Jewish people against foreign enemies. Manslaughter is also listed as well with certain prescriptions for how to provide mercy to an individual who committed manslaughter vs. somebody who took life in cold blood in an unsanctioned manner. Further analysis of the Old Testament continues to show sanctioned killing for purposes of justice by civil leaders and warriors to include the punishment of murder. Thus, the 6th commandment really should be read "Thou Shalt Not Murder."

In the New Testament, one of the most poignant examples that validate the warrior profession is found from the writings of Luke, a doctor who transcribed many action scenes from the life of Jesus of Nazareth as well as one of the early founders of the Christian religion, Paul, who was formerly known as Saul of Tarsus.

During a moving scene found in the 7th chapter of the ancient manuscript of Luke, a Roman Centurion sends a message to Jesus asking for the divine favor and healing of one of his sick servants. The centurion goes on to say that he, like Jesus, is a man under authority and he gives commands that are expected to be obeyed to his servants. As such, he trusts that Jesus can just say a word without even physically meeting his servant based on the Centurion's faith that Jesus is under the divine authority of God to heal humans miraculously. Jesus marvels at this comment and says explicitly, "he has not seen such faith in all of Israel". Jesus never tells the centurion to leave his life as a soldier which he most likely would have if Jesus felt this was a sinful occupation. Jesus tells a woman caught in adultery to leave her life of sin and even requests a rich young ruler to sell what he has and give to the poor and then come follow Jesus. However, no such requirement is stated for this centurion. Later Luke describes in the book of Acts multiple accounts of Roman soldiers and civil peace officers such as a jailer who protect Paul. Many of them were accepted by God through faith without being asked to change their professions. Paul himself writes in the 13th chapter of a letter to Christians living in Rome that followers of Jesus of Nazareth should be submissive to government authorities who do not bear the sword without reason and who are avengers of God to punish evil doing. In other words, government authorities are given a specific responsibility and subsequent authority to use force up to and including lethal force to keep in check crime, rebellion, and lethal threats to populaces under the care of rulers and magistrates here on earth.

Various sects of the Judeo/Christian worldview feel that killing is never sanctioned, but the majority of those subscribing to this worldview find that the profession of arms is in keeping with their faith. If the majority view is taken, then this would relieve the warrior's soul of guilt for wrongdoing when they in fact lawfully under legitimate government authority took life when necessary to protect others from criminals and actors who pose a threat to the well-being of other local, national, and international communities.

In previous blot posts, Spiritual Fitness is Crucial to Maintaining Combat Readiness and Faith Can Be a Game Changer to Unit Combat Readiness that I previously wrote, I mentioned how as a young midshipman preparing for a career as a military officer, I struggled to answer a few life-changing questions as I prepared to sign my “2 for 7” papers at the US Naval Academy in 2007:

1) “Is it ok for me to kill another human in war?”

2) Where do I go when I die?

3) Is there a God, and if I can know Him, what does He want me to do with my life?

These are pretty fundamental questions that a lot of people before me have asked. Men like Sergeant Alvin York, World War I Medal of Honor Recipient in particular struggled with the first question I pose. Alvin at one point was considering becoming a conscientious objector to serving overseas in World War I as he had become a Christian and felt that he couldn't in good conscience kill another man because it conflicted what he knew about his faith at the time. His Commanding Officer knew the Bible on that issue better and encouraged Alvin to take time off and study the Bible better before coming back to make his final decision. During that time, Alvin realized that his faith in Christ and military service was not incompatible and he ended up going downrange to serve in the US Army during World War I. While serving in the 82nd Infantry Division, he captured a total of 132 German soldiers after taking out multiple machine-gun nests based on his expert marksmanship skills. I wonder what would have happened that day if Alvin had decided not to press into knowing his faith better. Might there have been a significant battlefield loss and a lot of Americans killed? I don’t know. What I can tell though was the encouragement of Alvin's leadership to understand his faith better made a tangible impact on the battlefield.

On the other hand, if you have watched the movie “Saving Private Ryan”, you have likely seen the scene where Corporal Upham fails to take life on the battlefield when it was warranted which ultimately got his fellow soldier killed in brutal hand to hand combat. I don’t know what happened to Corporal Upham after the war, but I wonder if he faced tremendous guilt and a moral injury for not taking life when he needed to which is just as bad I think when a service member takes like unjustly such as one sees in the opening scenes of the same movie where soldiers mock and eventually kill surrendering German soldiers.

I am very passionate about this issue personally because this was an issue as I stated before that I had to tackle but ultimately came to the conclusion that I could serve in the profession of arms. If I had not successfully answered this question, the chances of my ability to make a difference in the lives of many Marines and service members as well as my country with 13+ years of active service and 3 deployments might never had happened. While I have never had to physically shoot a gun in anger at an enemy combatant, I have participated in combat operations to include providing operational support to AV-8B pilots dropping bombs on Taliban insurgents in Afghanistan to include helping with mission debriefs and sending up edited bombing footage to higher headquarters. Moments like these were sobering but I was prepared for them. If you a chaplain and you’re reading this, I would encourage you to ensure that the service members you serve, especially if they are in a combat arms unit, understand this issue well. If you’re a military leader, I also hope that you understand the implications of what I’m sharing here even if you don’t subscribe to a Judeo/Christian worldview. I hope that this knowledge becomes part of the ethical flak vest and kevlar needed to withstand the intense psychological and spiritual tensions related to taking the life of another human being even when done lawfully. If you are interested in checking out a YouTube video I did on this subject, please go here: "Thou Shalt Not Kill?"


If you liked this article as it relates to the concept of training military members to be physically, mentally, and spiritually prepared for the violence of combat, then you’ll likely like these articles as well as this YouTube channel dedicated to educational videos I have facilitated on various subjects related to military service. Please free to leave a comment and share with me the insight you have on the topic and what you do to talk about this issue with service members or veterans.

Fit for the Fight and Life,

Chris Reardon

Major, US Marine Corps


Freedom Fitness America

While a sophomore at the US Naval Academy in 2005, Chris struggled to understand the difference between killing and murder in combat along with figuring out influential yet ethical leadership in the profession of arms. Through personal research and mentoring, he resolved these issues and continued to become an active duty Marine Corps Officer with 13+ years of active service that included three deployments to units ranging from aviation and infantry units to higher headquarters. During this time he pioneered new methods of military life coaching with multiple branches of service through collaboration with chaplains and unit leaders along with civilian business and church leaders which ultimately led to his founding of the fiscally sponsored non-profit organization, Freedom Fitness America which facilitates training for military professionals to be fit for the fight and life; namely physically, mentally, and spiritually prepared for the violence of combat and tackling the obstacles of everyday life.