At the time of Christ, Roman power had neared its peak. Roman troops controlled a vast area stretching from England to the Black Sea and from the Rhine River to the deserts of North Africa. Though it was the most powerful government in the world, the Republic had fallen and been replaced by military dictators. Rome was notorious for its decadence and corruption. In spite of Roman corruption, the apostle Paul clearly set forth the principle that secular government is God’s agent to maintain the rule of law on earth (Romans 13:1-7). Because Paul addressed this principle to the Christian community in Rome, it is clear that the fact of governmental corruption doesn’t overrule the need for governmental authority. Human nature as it is, it’s hard to imagine civilized life without the influence of governmental power through police, courts, and legislatures. In fact, it was Roman justice, as flawed as it was, that protected Paul from certain death at the hands of his fellow Jews (Acts 23).
It is interesting that in spite of Rome’s corruption, her centurions were widely respected as men of competence and integrity. Polybius wrote that centurions “were chosen by merit, and so were men remarkable not so much for their daring courage as for their deliberation, constancy, and strength of mind.” All of the centurions mentioned in the New Testament are praised as Christians, God-fearers, or men of good character (Matthew 8:5,8,13;27:54; Mark 15:39,44-45; Luke 7:2,6;23:47; Acts 10:1,22;21:32;22:25-26;23:17,23;24:23;27:1,6,11,31,43;28:16).
Although honorable men of a pagan background served as officers in the Roman army, the early church was opposed to Christians in the military. Kenneth Scott Latourette wrote:
For the first three centuries, no Christian writing which has survived to our time condoned Christian participation in war. Some Christians held that for them all bloodshed, whether as soldiers or as executioners, was unlawful. At one stage in its history the influential Church of Alexandria seems to have looked askance upon receiving soldiers into its membership and to have permitted enlistment in the legions only in exceptional circumstances (A History of Christianity, pp. 242-243).
Adolf von Harnack summarized the reasons for Christian opposition to involvement in the military:
The shedding of blood on the battlefield, the use of torture in the law-courts, the passing of death-sentences by officers and the execution of them by common soldiers, the unconditional military oath, the all-pervading worship of the Emperor, the sacrifices in which all were expected in some way to participate, the average behaviour of soldiers in peace-time, and other idolatrous and offensive customs—all these would constitute in combination an exceedingly powerful deterrent against any Christian joining the army on his own initiative.
The early church, having a realistic view of the necessity for governmental authority but no illusions about its primary loyalty to Christ, didn’t approve Christian military involvement. Only after Constantine’s conversion made Christianity the favored religion in the empire did a destructive process begin that merged the religious authority of the church with the political and judicial power of the state. Soon Christians could no longer easily distinguish between the authority of Christ and of Caesar–usually with tragic consequences