The strong pacifism of the early Christians can be seen through the historical and literary evidence, which demonstrates that until about 170 CE there was no apparent Christian involvement within the military structure, and that the first statements regarding such involvement were condemned for running counter to the true teachings of Jesus Christ. Until the advent of Augustine, the preeminent theologian was Origen, who, towards the end of the second century, commented on the passage 'the one who takes the sword shall perish by the sword'. For Origen this was an injunction on the part of Christ to his followers to clothe themselves in the spiritual sword while casting away the warlike sword, and to be on guard lest 'for warfare, or for vindication of our rights, or for any occasion, we should take the sword; for no such occasion is allowed by this evangelical teaching' (Windass, 12). Origen further adds in a different situation: 'We do not draw the sword against any nation, and we no longer learn to fight, because we have become, thanks to Jesus, Sons of Peace' (Dom Bede Griffith OSB, 72).
Let us reflect on Origen's words:
The assertion that "certain Jews at the time of Christ revolted against the Jewish community and followed Jesus" is not less false than the claim "that the Jews had their origin in a revolt of certain Egyptians." Celsus and those who agree with him will not be able to cite a single act of rebellion on the part of the Christians. If a revolt had indeed given rise to the Christian community, if Christians took their origins from the Jews, who were allowed to take up arms in defense of their possessions and to kill their enemies, the Christian Lawgiver would not have made homicide absolutely forbidden. He would not have taught that his disciples were never justified in taking such action against a man even if he were the greatest wrongdoer. [Jesus] considered it contrary to his divinely inspired legislation to approve any kind of homicide whatsoever. If Christians had started with a revolt, they would never have submitted to the kind of peaceful laws which permitted them to be slaughtered "like sheep" (Psalm 44:11) and which made them always incapable of taking vengeance on their persecutors because they followed the law of gentleness and love. (Against Celsus 3.8)
To those who ask about our origin and our founder we reply that we have come in response to Jesus' commands to beat into plowshares the rational swords of conflict and arrogance and to change into pruning hooks these spears that we used to fight with. For we no longer take up the sword against any nation, nor do we learn the art of war any more. Instead of following the traditions that made us "strangers to the covenants" (Eph 2:12), we have become sons of peace through Jesus our founder. (Against Celsus 5.33)
Denying to the Jews of old, who had their own socio-political system and their own territory, the right to march against their enemies, to wage war in order to protect their traditions, to kill, or to impose some kind of punishment on adulterers, murderers and others who committed similar crimes would have been nothing short of consigning them to complete destruction when an enemy attacked their nation because their own Law would have sapped their strength and would have forestalled their resistance. But Providence, which in an earlier time gave us the Law and now has given us the Gospel of Jesus Christ, did not want the Jewish system perpetuated and so destroyed the city of the Jews, and their temple along with the divine worship that was celebrated thew through sacrifices and prescribed rites. (Against Celsus 7.26)
Quoted in Helgeland, John, et al. Christians and the Military: The Early Experience. (Minneapolis: Augsburg, 1985).
The harshness of the Church towards those who violate this precept can be seen in the condemnation of those Christians who undertake military service. Towards the end of the second century Clement of Alexandria in the document Apostolic Tradition (written about 217 CE) declares 'that he who holds the sword must cast it away and that if one of the faithful becomes a soldier he must be rejected by the Church, for he has scorned God' (Ellul, 11). Another contemporary of Origen, St Cyprian, lamented that 'murder is a crime if one person commits it; but it is claimed as virtuous and brave if many commit it. So it is no longer innocence, but the enormity of the crime that ensures exemption from punishment' (Stratmann, 19).
Generally it may be seen that until the fourth century, Christians refused to do military service, and legends have handed down to us traditions of converted soldiers suffering a martyr's death rather than revert to military service. It is reputed that Maximilian was martyred for this reason, despite the fact that he was the son of a soldier and a soldier himself prior to his conversion. 'I cannot be a soldier, I cannot do evil, because I am a Christian,' are his reputed words. The same may be said of St Martin of Tours, who would rather accept death than kill in military service.
Tertullian, who is the first to mention the presence of Christians in the imperial army, also condemns them, saying that 'Christ, in disarming Peter, ungirt every soldier' (Bainton, 73). He writes:
But now the question is whether a believer can become a soldier and whether a soldier can be admitted into the faith, even if he is a member only of the rank and file who are not required to take part in sacrifices or capital punishments.
There can be no compatibility between the divine and the human sacrament (= military oath), the standard of Christ and the standard of the devil, the camp of light and the camp of darkness. One soul cannot serve two masters-God and Caesar. Moses, to be sure, carried a rod; Aaron wore a military belt, and John (the Baptist) is girt with leather (i.e., like a soldier); and, if you really want to play around with the subject, Joshua the son of Nun led an army and the people waged war. But how will a Christian man go to war? Indeed how will he serve even in peacetime without a sword which the Lord has taken away? For even if soldiers came to John and received advice on how to act, and even if a centurion became a believer, the Lord, in subsequently disarming Peter, disarmed every soldier, No uniform is lawful among us if it is designated for an unlawful action. (Treatise on Idolatry 19; Ante-Nicene Fathers 3:73)
Quoted in Helgeland, John, et al. Christians and the Military: The Early Experience. (Minneapolis: Augsburg, 1985).
With regard to official regulations about service within the military forces at this time, we possess the Canons of St Hippolytus, who drew up his regulations in order to defend 'the traditional practices of the Church against recent error and the apostasy of ignorant men' (Beks, 102). There he makes it quite clear that if a man served in the army of the emperor, then he should not be accepted as a Christian, and also that if a catechumen showed military aspirations then he should also not be received into the fold of the Church. His Canons further stated that 'a soldier of civil authority must be taught not to kill and to refuse to do so if he is commanded' (Beks, 102).
If a catechumen or a baptized Christian wishes to become a soldier, let him be cast out. For he has despised God. (Gregory Dix, The Treatise on The Apostolic Tradition of St Hippolytus of Rome, 3rd rev, [London: Alban Press, 1937], 26 - 7)