It is certainly true that Christians are called to “turn the other cheek” in Matthew 5:39, and it is also true that Jesus said to “love your enemies” in Matthew 5:44. From the Old Testament, Exodus 20:13 and Deuteronomy 5:17 both command, “Thou shalt not kill.” If one was so inclined, they could use these verses to paint a rather clear picture, and that is precisely what Churchians, secularists, and atheists have done to subvert the faith. But would such a picture actually be representative of Christianity as traditionally understood?
First, let’s be clear that pacifism was indeed once espoused by some early leaders within the Church. For example, as summarized by St. Thomas Aquinas (1225-1274), St. Augustine of Hippo (354-430) maintained that to kill in defense of one’s own life was unlawful, albeit he did allow for public officials and soldiers to kill for the sake of others (Source). Pope Nicholas I (800-867) said that he gave no permission for clerics to kill another human being for any reason including self-defense (Source). It should be noted, however, that St. Thomas addressed these objections and instead came to the conclusion that self-defense was lawful so long as the intention was defense rather than to kill and there was no malice underpinning one’s actions.
Second, let’s address the passages above used to claim that Christians must be pacifists. For example, in Matthew 5:38-39, Jesus said, “Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.” The context here is important. The word used for “evil” is ponero/πονηρῷ, related to poneros/πονηρός. This can be understood as “wicked” or “malicious,” from ponos/πόνος (pain). This “evil” could be in the grander sense of our understanding, but it can also mean someone toiling to cause us problems. The proper meaning is clarified when we consider that the word for “smite” is rhapizei/ῥαπίζει, a simple strike or slap, and Jesus says to “turn the other cheek.” Slapping a person on the right cheek was understood to be a personal insult, and Jesus is telling his followers that they should not retaliate within that narrow context. Previously in Matthew 5:17, however, Jesus says, “Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.” We can thus see that Jesus is not undermining “tooth for a tooth, eye for an eye” as a matter of law, and the examples of what you should not retaliate against are personal in nature and are not deadly. Similarly, the word for “enemy” in Matthew 5:43-44 is derived from echthros/ἐχθρὸς (someone or something hated or hostile). Compare this to polemios/πολέμιος, which was derived from polemeo/πολεμέω (to make war). Again, Jesus was clearly speaking of one not holding personal hatred in their lives, not commanding us to accept criminal or foreign violence.
Now, we can see that some within the early Church suggested to one extent or another that Christians should not take the life of another, and perhaps the most preeminent thinker of that time was St. Augustine, who made allowance for public officials and soldiers to kill as needed. By the 13th century, St. Thomas Aquinas was justifying Christians defending themselves and the innocent so long as their intent was to defend themselves and not to purposely kill the attacker. This change makes sense against the backdrop of the Crusades. Indeed, the Sixth, Seventh, Eighth, and Ninth Crusades were all conducted within the lifetime of St. Thomas, and other important churchmen such as St. Bernard of Clairvaux had openly preached the crusade. It is not sufficient for us to rest our hat on the notion that “attitudes change,” however, because those who subvert Christendom readily use the argument that anyone who defends the faith is actually violating God’s commandments. We must instead show that the militant Christianity of the Middle Ages was not at odds with God’s will and that traditionalist Christians are right to take up the cross and sword once again.
To demonstrate God’s will on the subject, let’s first begin with the fact that the Old Testament does not directly address the issue of self-defense in a clear-cut fashion, but that does not mean that it is not addressed. For example, in Exodus 22:2-3, it is said that you would not face punishment for killing a thief who was breaking into your home at night, but you would be held liable if you killed him in daylight. Both scenarios involve the same homeowner facing the same thief, so why is it only permissible to kill the thief at night? Simply put, you cannot be expected to discern the thief’s intentions at night, and it was naturally assumed that the homeowner could defend himself when facing a possible threat. During the day, however, the homeowner could see that the thief was simply stealing rather than being a threat, and he should then be captured and forced to pay restitution for anything he was attempting to steal. This passage does not directly address self-defense, but it does make it clear that killing another was permissible if it was reasonable for you to assume that they were a threat. Why else would it make a distinction justifying the killing?
If a homeowner can kill so as to defend himself and his family, why then would we assume that Jesus expected his followers to submit to similar criminal violence? After all, God the Son did not come so as to subvert God the Father, so we should never assume that the former is contradicting the latter when the two can be easily understood and reconciled. Furthermore, we can see from the Old Testament that righteous warfare can not only be justified but was often commanded by God, and such warfare was certainly not weak or passive. For example, Hosea 13:16 says, “Samaria shall become desolate; for she hath rebelled against her God: they shall fall by the sword: their infants shall be dashed in pieces, and their women with child shall be ripped up.” In 1 Samuel 15:3, we see something similar: “Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.” And in Numbers 31:17-18: “Now therefore kill every male among the little ones, and kill every woman that hath known man by lying with him. But all the women children, that have not known a man by lying with him, keep alive for yourselves.” Clearly, God expected the righteous to engage in warfare, which included commandments to brutally deal with certain enemies to the point of committing outright genocide to end any future threat.
In light of this background, let us now consider Luke 22:35-36: “And he said unto them, When I sent you without purse, and scrip, and shoes, lacked ye any thing? And they said, Nothing. Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one.” Indeed, in John 18:10-11, we see that Peter was armed as the Pharisees came to arrest Jesus, and, when he attacked the high priest’s servant, Jesus merely said that what was happening had to occur according to God’s will. Jesus did not condemn Peter for being armed, which makes sense considering He had commanded it, but He also did not condemn him for using the sword in and of itself. This is extremely important because there would be absolutely no reason for pacifists to carry swords, and, likewise, we should expect Jesus to have chastised Peter if somehow the swords were never meant to be used for any reason.
Those who espouse the notion that Christendom must be weak and that Christians must be pacifists would claim that Luke 22 is at odds with Matthew 5, but is it really that difficult to reconcile the two? Jesus commanded his followers to arm themselves even if they had to sell their cloaks to do so, but He also called on them to not bear hatred for people who wronged them in their day-to-day lives. Exodus 22 shows us that killing in self-defense can be justified, and numerous passages throughout the Old Testament highlight that war can also be justified, even righteous. None of this is contradictory because whether or not one’s actions are justified depends on the specific context in which one is acting. If you hate a person and kill them, that is clearly murder. If you bear them no ill will yet have to defend yourself or others, then you bear no guilt for slaying them. Again, God the Son cannot contradict God the Father, and the latter commanded righteous warfare while the former commanded his most loyal followers to arm themselves. Crusaders were not following bad theology or exposing themselves as hypocrites when they took up the cross and sword, but they were rather doing exactly what they were called to do in the name of the Father, the Son, and the Holy Spirit.