“Thou shalt not kill” is probably one of the best-known commandments in the Bible, but more complex than it appears. Throughout history, Christians have debated the context of this commandment and how they should apply it to subjects like war and revenge, unborn children and abandoned orphans, incarceration and execution. Here is what you need to know about this commandment and its place within orthodox Christian thought.
Which of the 10 Commandments Is 'Thou Shalt Not Kill'?
The 10 Commandments are listed twice in the Old Testament: Exodus 20:2-17 and Deuteronomy 5:6-21. “Thou shalt not kill” appears in Exodus 20:13 and Deuteronomy 5:17. The King James Version lists it as the sixth commandment, but not all Christians refer to it as the sixth commandment. This list of 10 commandments is a single unit in the original documents. Still, it belongs to a much larger list of commandments, covering everything from hygiene to sabbath regulations, contained in the Torah.
Various scholars within Christianity and Judaism have argued about which commandment is the greatest, which would also mean changing the order to list the commandments. As a result, in Roman Catholicism, “thou shalt not kill” is listed as the fifth commandment. In Protestantism and modern-day Judaism, “thou shalt not kill” is listed as the sixth commandment.
How Does 'Thou Shalt Not Kill' Apply to Murder?
One of the clearest applications of “thou shalt not kill” is that people are not permitted to murder each other. Later teachings in the Torah outline exceptions for self-defense (Exodus 22:2-3) and manslaughter (Deuteronomy 19), while calling deliberate murder a crime worthy of the death penalty (Exodus 21:12, Numbers 35:16-17). Life is precious and should not be taken lightly.
Jesus confirmed the value of self-defense (Luke 22:36) while teaching his followers to avoid “eye for an eye, tooth for a tooth” revenge (Matthew 5:38-39). Today, Christians discuss whether to apply Old Testament teachings about the death penalty to murder convictions (given the fact Israel was a theocracy and not a modern democracy, and concerns about systemic racism in the American prison system). Even Christians who approve of the modern death penalty argue for greater legal accountability, and few would argue the Bible promotes vigilante justice to kill murderers who escape justice.
How Does 'Thou Shalt Not Kill' Apply to War?
Historically, Christians have interpreted how “thou shalt not kill” applies to war in various ways. Does God’s command not to kill mean Christians cannot serve in wars?
Several writers have argued that essentially, the early church practiced pacifism—discouraging each other from military service, on principle. Reverend Kevin Dougherty cites quotes from the writings of the church fathers (including Clement of Alexandria, Tertullian, and the Didache) to support this claim.
Other writers, such as Andrew Holt, have argued that early Christians held complex views. Many early Christians did serve in the Roman Empire at least after the first century, and early churches tended to be more pro-war service if they lived at Rome’s borders (where they faced lots of invaders).
At this point, it’s important to remember that since Christianity was usually illegal and frequently persecuted until Constantine changed things in 313 A.D., the early church couldn’t meet publicly to check and discuss each other's views. Christians mostly met secretly, passing writings undercover, and holding religious debates in limited settings. Hence, early Christians maintained their primary beliefs (like Jesus’ virgin birth) but had widely differing views on secondary beliefs (like whether to immerse or sprinkle in baptism).
It wasn’t until Augustine’s writings that much of what we call orthodox Christian thought was organized into a clear system and publicly established in print for all to see. For example, James S. Spiegel argues in Hell and Divine Goodness that before the Council of Nicaea, most early church fathers leaned toward annihilationism (that sinners slowly have their souls annihilated in hell). Augustine’s support for eternal conscious torment (sinners suffering eternally in hell) changed that emphasis completely, taking Western Christianity in a different direction.
Augustine also started Christian arguments for just war theory—the idea explored by various pagan thinkers that a war might be morally justifiable, and ergo a soldier could kill other soldiers without being a murderer. Augustine makes the following argument in Volume 2, Book 1, Chapter 21 of The City of God:
“They who have waged war in obedience to the divine command, or in conformity with His laws, have represented in their persons the public justice or the wisdom of government, and in this capacity have put to death wicked men; such persons have by no means violated the commandment, ‘Thou shalt not kill.’”—Of the Cases in Which We May Put Men to Death Without Incurring the Guilt of Murder
After Augustine, scholars (notably Thomas Aquinas) have argued and developed new ideas about just war theory. Various just war advocates have argued about what qualifies as a just war, how much violence a Christian can commit, and whether it’s acceptable to commit violence as a soldier or in other contexts. For example, some have argued that Allied soldiers killing German soldiers in World War II didn’t break “thou shalt not kill.” Many would argue the same principle applies to Danish resistance fighters who killed Germans while blowing up munition trains.
On the other hand, some Christian scholars (particularly in the Anabaptist tradition) have argued that Christians are always called to follow Christ’s command to love their persecutors and enemies, even in violent times. German theologian Eberhard Arnold argued for pacificism even after Gestapo agents raided his offices, keeping anti-war theology in his magnum opus Inner Land.
Various Christians have fallen in between these two positions. Dietrich Bonhoeffer held pacifist views during the 1930s and seemingly shifted his views when he joined a plot to kill Hitler. Many have argued Bonhoeffer became a reluctant just war theory advocate; a few have argued that he stayed a pacifist but concluded killer Hitler was the lesser, necessary evil.
How Does 'Thou Shalt Not Kill' Apply to Abortion?
Disclaimer: This section includes references to abortion, infanticide, and other sensitive topics, without graphic details.
Orthodox Christians have debated how to apply “thou shalt not kill” to war in various ways. However, they have more consistently maintained that this command makes abortion wrong. Later commands to “look after orphans and widows” (James 1:27) support this position—Christ’s followers are called to help and support people who have no one to support them, including the unborn.
In the early church, this emphasis on helping orphans and discouraging the death of infants seemed radical. By and large, ancient pagan societies did not believe all humans had value—a few, generally the strongest or best nurtured, had value. Children from the right families had value. Others were seen more or less as commodities—Pascal-Emmanuel Gobry observes, “various pagan authors describe children as being more like plants than human beings.”
Joanie Gruber observes that some ancient civilizations had a limited value for unwanted children—for example, ancient Athens cared for infants whose fathers had died fighting in wars. However, most children with no parents or guardians were left to die, frequently by exposure (literally left outside to starve or be eaten by animals).
“Infanticide was universal in ancient Greece and Rome. Babies would often be rejected if they were illegitimate, unhealthy or deformed, the wrong sex (female for example), or too great a burden on the family. Female infants were particularly vulnerable.”—Joannie Gruber, “Orphan Care in the Early Church”
Early Christians became known not only for supporting orphans and widows of other Christians but also for extending that charity to orphans and widows of non-Christian families. Julian the Apostate complained about Christian charity in at least two of his letters, that his pagan priests were overlooking the poor and Christians were filling that gap, even being kind to strangers.
After Christianity gained political power, much of this humility and service was lost. However, even amid the medieval church’s worst abuses, some Christians kept this principle alive. For example, Pope Innocent III decreed that Italian mothers who couldn’t care for their children could leave them in “foundling wheels” at churches where nuns and monks would care for them.
In contemporary times, Christians have gone back and forth on this issue. Christians who follow historically orthodox religious values maintain that all human life has basic dignity, making abortion morally wrong. Consequently, theologically conservative Christian groups (both Catholic and Protestant) have supported pro-life government policies.
However, there are areas of nuance even within pro-life Christian circles that people need to understand. Some pro-life Christians discuss whether abortion should be legal based on concerns such as:
- If medical complications mean a mother may die before or during childbirth, is it moral to terminate the unborn child?
- If abortion services are not legally available (and therefore subject to certain standards), will women resort to illegal methods?
Medical doctor (and former Planned Parenthood employee) Patti Giebink answers some of these concerns in Unexpected Choice. Giebink cites many advances (medical, social, and cultural) since Roe v. Wade that provide safer, better options for pregnant women. She also discusses statistics of how many women suffer from medical or mental health issues after legal abortion procedures, countering claims that abortion is harmless.
Sometimes, these discussions intersect with Christian debates about reproductive technology. For example, if couples undergoing in vitro fertilization (IVF) use genetic screening to ensure they don’t have children who inherit their medical conditions… are they making the same choice as women who get abortions to avoid carrying children with Down Syndrome? Different pro-life Christians have very different stances on that.
How Should Christians Respond to Debates about 'Thou Shalt Not Kill'?
Because each implication of “thou shalt not kill” raises complex questions, Christians will inevitably meet other believers who hold different views on it. Regardless of their views, they must have something vital: charity and a willingness to listen. Charity and willingness to listen don't just matter because the Bible commands Christians to live together in brotherly love (Romans 12:9-10). They matter because the Bible isn’t written in a way that permits Christians to argue like two sports referees going over a manual. Manuals are written in clear language, without personal stories, in styles requiring no context.
Ellen Painter Dollar highlights this truth in an essay about Christians and reproductive technology. She reminds readers, “the Bible lacks crystal clear ‘do this, don’t do that’ language about reproductive decisions,” instead communicating those ideas through stories. Stories have ideas Christians can clearly apply to their lives, but stories always require listening and noting context (who is talking, where they come from, etc.). Dollar's advice applies not only to reproductive technology but to abortion, war, the death penalty, and other complex topics:
“The biblical story is, like all stories involving human beings, full of complexity, nuance, inconsistency, and surprise. Anytime we examine reproductive issues through a theological lens, we must engage with people’s stories, understating that those stories in all their complexity, nuance, inconsistency, and surprise will complicate our discourse but also deepen it… The first and more important step in discussing a Christian perspective on reproductive issues is to listen, long and well, to the stories of people who have made difficult and complex reproductive decisions.”—Ellen Painter Dollar, “A Broad Approach to Reproductive Ethics” (in Cultural Engagement)
Further Reading:
Does “Thou Shalt Not Kill” Apply to Abortion?
The History of the Idea of ‘War Crimes’
Does the Death Penalty Violate the Ten Commandments?
Photo Credit: Getty Images/Pontuse
G. Connor Salter has contributed over 1,400 articles to various publications, including interviews for Christian Communicator and book reviews for The Evangelical Church Library Association. In 2020, he won First Prize for Best Feature Story in a regional contest by the Colorado Press Association Network. In 2024, he was cited as the editor for Leigh Ann Thomas' article "Is Prayer Really That Important?" which won Third Place (Articles Online) at the Selah Awards hosted by the Blue Ridge Christian Writers Conference.
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