Introduction
The question of whether Christians could serve in the military was a topic of serious theological, ethical, and practical debate in the first five centuries of the Church. Living under Roman rule, early Christians wrestled with issues like violence, idolatry, and allegiance—often in tension with the demands of military life. While views were not uniform, many early Christian writers expressed caution or outright rejection of military participation.
A Church in Conflict with Empire
Early Christianity emerged within the Roman Empire, where military service was both a duty and a pathway to social advancement. However, Christians were often at odds with Roman practices—especially those involving violence and the worship of the emperor or other deities, common in military rituals.
Key Authors and What They Wrote
1. Tertullian (c. 160–220 AD)
Tertullian, an early Christian apologist from North Africa, was one of the most outspoken critics of Christians joining the military.
“Can a soldier’s life be lawful, when Christ has pronounced that he who uses the sword shall perish by the sword?”
—Tertullian, De Idololatria, Ch. 19
Tertullian also objected to the idolatrous practices involved in military oaths and rituals:
“Shall he carry a flag, too, hostile to Christ?”
—Tertullian, De Corona, Ch. 11
He viewed military service as incompatible with Christian identity due to its requirements to kill, swear oaths, and participate in pagan ceremonies.
2. Origen (c. 184–253 AD)
Origen, a theologian from Alexandria, did not advocate for Christian participation in the military but emphasized a spiritual warfare instead.
“We do not go forth as soldiers with the emperor, even if he demands this, but we fight on his behalf by offering our prayers to God.”
—Origen, Against Celsus, Book 8, Ch. 73
Origen affirmed that Christians supported the well-being of the empire—but through prayer and virtuous living rather than through violence.
3. Lactantius (c. 250–325 AD)
Writing shortly before Christianity became legalized, Lactantius spoke clearly against killing of any kind.
“It is not right to kill a human being, whom God has wished to be a sacred creature.”
—Lactantius, Divine Institutes, Book 6, Ch. 20
This was a blanket statement, applying both to civilians and soldiers.
Changes After Constantine
The conversion of Emperor Constantine and the Edict of Milan (313 AD) marked a major turning point. Christianity moved from being a persecuted minority religion to becoming aligned with imperial power.
- Post-Constantinian Shift: As more Christians entered public service, including the military, church leaders began to accommodate military service—especially as the empire came under threat from external enemies.
- Council of Arles (314 AD): One of the earliest formal recognitions of Christian soldiers, this council condemned soldiers who left the army during peacetime (Canon 3).
- Ambrose of Milan and Augustine of Hippo: These later figures introduced just war theory. Augustine in particular argued that war could be just if fought under proper authority and for righteous causes.
“The soldier, indeed, is not guilty of murder if he has carried out the orders of his ruler.”
—Augustine, Contra Faustum, Book 22, Ch. 74
Summary of Trends
- 1st–3rd centuries: Military service was largely seen as incompatible with Christian faith.
- Early 4th century: Tensions persisted, but shifts began as Christianity gained legal status.
- Late 4th–5th centuries: The rise of “Just War” thinking made Christian military service more theologically acceptable, though pacifist views continued to exist in some circles.
Conclusion
The early centuries of the Church reflect a complex and evolving stance on military service. While the earliest Christians leaned heavily toward pacifism and separation from imperial violence, the growing integration of Church and state after Constantine shifted Christian views. Understanding this development offers insight into the broader transformation of Christianity as it moved from the margins to the center of Roman power.
