What was the Church’s view of military service in the era before Constantine?

In the second century, the pagan philosopher Celsus blamed Christians for fleeing from the army and thus not defending the Emperor. Origen did not deny this accusation or say that it was a false accusation, for Christians did indeed refuse to participate in wars, much as did the pagan priests who were exempt from military service so that when they made their offerings, they would not do so with blood-stained hands, tainted by killing. For similar reasons, Christians also rightly claimed exemption.⁹¹² Origen pointed out that Christians were loyal to the state, except when it came to participating in an unjust war. In short, they could participate, but only if the war were a just war.

Origen says, “Unless those physical wars bore the figure of spiritual wars, I do not think the books of Jewish history would ever have been handed down by the apostles to the disciples of Christ, who came to teach peace, so that they could be read in the churches … In short, knowing that now we do not have to wage physical wars, but that the struggles of the soul have to be exerted against spiritual adversaries, the Apostle, just as a military leader,

911 Eusebius Pamphili, Life of Constantine 1.28 (NPNF II/1:490). Or, “By this sign you shall conquer.”

912 Origen of Alexandria, Against Celsus 8.73 (ANF 4:668–669).

gives an order to the soldiers of Christ, saying, ‘Put on the armor of God, so that you may be able to stand firm against the cunning devices of the Devil’ (Eph. 6:11).”⁹¹³

St. Augustine addresses the topic of those wars that God permitted the people to wage against the pagan nations. In his view, the eternal punishment that might befall the evil pagans is far graver than anything they might suffer through war or physical death. He says that “divine providence … is wont to reform the depraved manners of men by chastisement.”⁹¹⁴

In his response to Faustus, who criticized the wars of the Old Testament, St. Augustine says, “The account of the wars of Moses will not excite surprise or abhorrence, for in wars carried on by divine command, he showed not ferocity but obedience; and God in giving the command, acted not in cruelty, but in righteous retribution, giving to all what they deserved, and warning those who needed warning … 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 authority, good men undertake wars, when they find themselves in such a position as regards the conduct of human affairs.”⁹¹⁵

He also says, “And in mercy, also, if such a thing were possible, even wars might be waged by the good, in order that, by bringing under the yoke the unbridled lusts of men, those vices might be abolished which ought, under a just government, to be either extirpated or suppressed.”⁹¹⁶