One might be willing to grant that the just war concept sounds reasonable and just, when considered in the context of secular moral philosophy and international politics. But we are Christians, and our conclusions concerning this and all other issues must be grounded in the will of God as given to us in the Bible.
Thus we must ask, and not just once, but every time conflict disrupts peace... how can the idea of a just war be embraced by those who accept the Bible as God’s inerrant Word, and who are fully aware that it teaches us not to murder, to love our enemies, and to turn the other cheek when attacked? Is participation in a just war consistent with all the teaching of the Bible?
We note first that God himself has ordained civil government (the institution, not individual governments) for the express purpose of protecting innocent citizens from being treated unjustly (Romans 13:1-4; 1 Peter 2:14). This includes the legitimate use of lethal weaponry to bring retributive justice upon those perpetrating evil upon the innocent (Romans 13:4). In other words, one of the God-given purposes of civil–government is to protect the innocent through methods of self-defense against aggressor nations or groups. This is the basic foundation of the just war concept.
We must also recognize that God’s Word makes a distinction between what is required of individuals when they are subjected to attack, and what is required of governments when such attacks occur (either upon individuals or upon the nation as such). This distinction is emphasized in the Old Testament, especially in the Law of Moses. The government (judges and civil leaders) was intended to apply eye-for-eye justice against evildoers. The three eye-for-eye texts (Exodus 21:23-25; Leviticus 24:17-21; Deuteronomy 19:21) refer not to individuals but to courts of law. This extended to warfare itself, which was of two kinds: defensive (Exodus 17:8-16) and judicial (Numbers 31:1).
At the same time the Law of Moses establishes a different standard for interpersonal relationships: neighbor-love is commanded, while hatred and retaliation are forbidden: “You shall not hate your fellow countryman in your heart... You shall not take vengeance, nor bear any grudge against the sons of your people, but you shall love your neighbor as yourself; I am the Lord” (Leviticus 19:17, 18).
Many Christians have assumed that such teaching was first given by Jesus in the Sermon on the Mount (see Matthew 5:38-48), but that assumption is incorrect. The distinction between governmental retributive justice (as exercised in defensive warfare) and the prohibition of individual vengeance has always been God’s purpose for his people.
We see the same distinction in Paul’s teaching in Romans 12 and 13. His teaching about government as God’s instrument of justice in Romans 13:1-4 is immediately preceded by the prohibition of personal retribution in Romans 12:17-21. He says it very clearly in verse 17... “Never pay back evil for evil to anyone”) and verse 19 (“Never take your own revenge, beloved, but leave room for the wrath of God, for it is written...‘Vengeance is mine, I will repay,’ says the Lord.” Paul then explains that God exacts such vengeance—his own vengeance—through civil government (Romans 13:4).
When Jesus teaches in Matthew 5:38... that we must not just resist evil, but must turn the other cheek, he is not repudiating the justice principle meant to be used by civil government but is repeating only what God has always required of individuals when personally attacked. He is not introducing some new teaching, a so-called “higher law of love.” He is reminding us that it has always been wrong to use the rules that apply to governments as a license for personal revenge. So said the Law of Moses, and so says the Apostle Paul. This is God’s will for us as individuals, and we make a grave mistake when we try to apply it to civil–government. It is perfectly consistent with the concept of a just war.
A third point, is that both of these standards (the one for individuals and the one for governments) are holy and right. Contrary to the teaching of many Christian pacifists, there is no hint that God’s will for governments, even the part about applying the sword, is somehow evil. Such pacifists grant that government’s use of force is sometimes necessary, but they regard it as a necessary evil which as such cannot be participated in by Christians. Thus the sphere of God’s kingdom and the sphere of civil government are mutually exclusive. Only the Christian way of nonviolence is right, while the government’s use of force and violence is evil—a necessary evil, to be sure, but evil nonetheless.
This interpretation is simply wrong. God himself has ordained government and appointed it as his own instrument for dispensing his own wrath and vengeance upon evildoers. God’s stated will for governments is no less good and moral and righteous than his stated will for individuals. When government is carrying out its divinely specified functions, it is doing what is “holy and righteous” especially when it is dispensing God’s retributive justice upon evildoers. And if it is right as such, then it is right for any human being to be a part of it, even a Christian.
Someone may object that participating even in a just war seems to contradict the whole ethic of love and the very nature of God as love. Two comments may be made. First, God is love (1 John 4:8), but he is not love only. He is also a consuming fire (Hebrews 12:29; see also Hebrews 10:30, 31), the fire of wrath and vengeance and retribution. Many pacifists forget this aspect of God’s nature.
The main point of the “just war concept” is not to maim and kill the enemy, but to protect the innocent and law-abiding. Would this not be an expression of neighbor-love? “Responsible love” is thus the ultimate basis for a Christian’s endorsement of the just-war concept.
