The Early Church and Military Service

*The following post is adapted from Preston Sprinkle’s forthcoming book: Fight: A Christian Case for Non-Violence (Colorado Springs: David C. Cook, 2013). Preston’s book is due to release on August 1.

In a previous post, I stated that “there was not a single Christian writer in the first three hundred years of Christianity who said that Christians should serve in Rome’s military.” My statement, however, deserves closer inspection since there were many Christians who served in Rome’s military; yes, even before Constantine.

Apart from the New Testament, which records several military leaders coming to Christ (Matt 8; Acts 10), we have evidence of a growing number of Christians in Rome’s military from A.D. 173 right up until A.D. 313 (Constantine’s edict to end persecution of Christians). Some of these were converted while serving in the military. Others may have joined as Christians. In any case, one thing is clear: early Christian writers condemned military service among believers.

Tertullian, for instance, wrote an entire treatise forbidding military service among Christians (The Crown) and such sentiment is found throughout his other writings (On Idolatry). Origen too condemned military service whenever he addressed the subject. And Lactantius agreed: “A just man may not be a soldier” (Divine Institutes, 6.20).

Now again, there were Christians in the military before Constantine. But as far as the opinion of early Christian writers goes, historian Alan Kreider was correct that “no Christian theologian before Constantine justified Christian participation in warfare” (“Military Service,” 431).

But this actually doesn’t tell us too much. The main question is not whether the theologians permit military service. This much is clear. They condemn it. The question, though, is why? On what grounds are Christians forbidden to join the military?

One reason is idolatry. The Roman military was inseparable from Roman religion; to serve one meant serving the other. It would have been virtually impossible to be a Christian soldier and not participate in idolatry. For instance, before embarking on a military campaign, soldiers would take part in various pagan rituals, including sacrificing sheep, bulls, and pigs to purify the army. Similar rituals dominated the postwar celebration. Throughout the legions, soldiers regularly burned incense and offered grain to local deities, and idolatrous symbols everywhere pervaded the camps.

It’s not that Christian soldiers couldn’t worship Jesus alongside other Roman gods. Well and good. But no soldier could worship a single deity (such as Jesus) without honoring the others. “[T]he totality of Roman army religion was an impressive system,” wrote one historian. “[It] would be impossible for any Christian in the army to avoid dealing with it in one way or another” (Helgeland et al., Christians and the Military, 54). Christians were clearly forbidden to join the military on account of idolatry.

But idolatry wasn’t the only reason military service was forbidden. Christians weren’t allowed to join because killing is wrong in principle. And several writers made this plain.

Lactantius, in the quote we read, said that “a just man may not be a soldier” and not because of idolatry. His reason was that “killing itself is banned” and “killing a human being is always wrong” (Divine Institutes, 6.20). Tertullian spoke out most frequently against Christians joining the military and often appealed to idolatry as the main reason. But killing was another reason. In arguing whether “a believer can become a soldier,” he unambiguously said no: “The Lord, by taking away Peter’s sword”—referring to the incident in Gethsemane—“disarmed every soldier thereafter.” Then, in the very next statement, Tertullian said: “We are not allowed to wear any uniform that symbolizes a sinful act.” That “act” refers back to wielding a sword that Jesus took away. Military service is wrong because killing is wrong. Origen also, in a lengthy treatise, said that Christians are not to participate in war, even if they are just wars (Against Celsum 8.73). His entire argument was governed by a rigorous defense of the nonviolent character of the Christian faith. Again, as Origen said earlier, Christians are prohibited from killing even the guilty.

The issue of killing was prohibited in every mention by early church writers. Whenever the issue of military service and warfare was discussed, Christians were prohibited from participating. Nowhere in the written record in the first three hundred years of Christianity is killing ever justified. Not even for soldiers.