Few theological quandaries are more controversial, and more emotionally provoking, than the relationship between faith and violence. What is the Christian response to war and conflict? What do we make of the violence of the Old Testament over and against the seeming pacifism of Jesus Christ? Should Christians arm themselves, or support capital punishment for major crimes?
Recent events and comments from public figures have spawned a particularly heated public debate over the Christian’s proper relationship to self-defense and the use of weapons. This debate is part of a larger conversation as Western Christianity is being forced to reevaluate its relationship to society and political life in the 21st century—what is the proper Christian witness in an age of terrorism, school shootings, religious violence, and debates about guns and national security?
Specifically, does God want Christians to arm themselves for the purpose of self-defense? Does God want Christians to arm themselves for the purpose of self-defense? Click To Tweet
What Does Church History Tell Us?
As with many contemporary controversies, some attention to Christian Tradition can help bring some clarity.
Church history reveals a (limited) spectrum of Christian opinions on questions of war, self-defense, civic justice, weapon ownership, etc. But the Church’s ultimate witness to peacefulness is something we find at the heart of the Christian Tradition. The Tradition contains a long-standing commitment to non-violence that should be treated with the utmost of seriousness.
Even if one believes in the existence of legitimate uses for violence, they must still also acknowledge peace and non-violence as fundamental and historic Christian values. If one believes in legitimate violence, they must acknowledge non-violence as a Christian value. Click To Tweet
Ambrose and Religious Liberty
To illustrate this, a case study: I want to consider one of the most important figures of early Christian history, Ambrose of Milan. Ambrose was bishop of Milan, in northern Italy (b.340-d.397 AD). Ambrose began his adult life with a career in government, but was later pressured into Church leadership. He became one of the most prominent bishops of his day, and his influence resounds throughout the centuries for his work on Christian ethics, Biblical exegesis, worship and liturgy, and ecclesiology. He is one of the first Christian leaders to think through the political issues inherent in his brave new world of Christian emperors and a more politically prominent Church. He set important precedents in preserving the Church’s independence from imperial meddling.
George Kalantzis’ very helpful book, Caesar and the Lamb , illustrates persuasively that before the age of Constantine, there was a firm Christian “non-violent” witness; at least as far as written theological treatises are concerned. That is, a strong conviction that violence in all its forms is un-Christian. Whether retributive, defensive, or military, violence is seen by these early theologians as deeply out of step for a people who worship a God who submitted to violence out of love for His enemies and attackers.
Did God Forbid All Killing?
The early Christian historian Lactantius is a representative example: “When God forbids killing, he doesn’t just ban murder, which is not permitted under the law even; he is also forbidding to us to do certain things which are treated as lawful among men. A just man may not be a soldier. . . nor may he put anyone on a capital charge: whether you kill a man with a sword or a speech makes no difference, since killing itself is banned. In this commandment of God no exception at all should be made: killing a human being is always wrong because it is God’s will for man to be a sacred creature” 
After Constantine became a Christian, the issue became more complicated. Increasingly nuanced arguments emerged as the Church tried to make sense of the Christian faith in light of a quickly Christianizing imperial court and public space.
While we find ourselves in a very different position in the West and the 21st century, I think we share with the era of Ambrose a quagmire of upheaval and ambivalence regarding the relationship between Christianity and society. We are stuck somewhere between the poles of Christianity as persecuted minority and cultural hegemon.
Was Ambrose a Pacifist?
Ambrose does not necessarily provide for us a systematic or complete answer to the questions of Christianity and violence. And to the extent that he does, we must recognize that his issues and concerns are different than our own. But he is instructive in his attempt to balance political realism with the Christian value of non-violence in this unsettled period.
Ambrose is probably not a pacifist in any sense we would recognize. He affirms that the Christian emperor has responsibilities in warfare to defend the Empire, and he presents something of a just war theory . He even contends that right worship of God on the part of the Emperor will ensure, or at least make more likely, military victories.
Speaking of David, “he never entered on a war without seeking counsel of the Lord. Thus he was victorious in all wars, and even to his last years was ready to fight” . Furthermore, Ambrose also appears to approve of the use of violence to defend others (at least as exercised by rulers), specifically the vulnerable . With each of these issues, it should be noted, Ambrose is not always clear when he is being morally decisive or referencing war and defense metaphorically.
Ambrose very clearly avoids any approval of violence, however, when talking about the Church herself. This reveals a fundamental conviction of Ambrose: Violence should in no way be permitted to stain the purity of the Church. A fundamental conviction of Ambrose: Violence should never be stain the purity of the Church. Click To Tweet
Heretics and Their Church Buildings
In one particularly dramatic scenario from his career, Ambrose strives to protect Church buildings from being seized by the imperial forces and transformed into places of worship for the heretical Arians. Ambrose engages in a variety of non-violent forms of political resistance, including something of a ‘sit-in:’ Pledging to remain in the basilica and compel the emperor to either forcibly remove or martyr him.
Ambrose addresses the emperor in a letter on this matter, clarifying that the Church does not engage in violence,
“we beg, O Augustus, we do not battle. We are not afraid, but we are begging. It befits Christians to hope for the tranquility of peace and not to check the steadfastness of faith and truth when faced with danger of death. The Lord is our Head who will save those who hope in Him” .
Ambrose specifically sees violence as immoral for clergy. Speaking of priests he says, “it is not our business to look to arms, but rather to the forces of peace” .
What About Self-Defense?
Most relevant to today’s conversation is where Ambrose, in one of his dogmatic treatises, directly addresses the question of self-defense:
“…yet I do not think that a Christian, a just and a wise man, ought to save his own life by the death of another; just as when he meets with an armed robber he cannot return his blows, lest in defending his life he should stain his love toward his neighbor. The verdict on this is plain and clear in the books of the Gospel. Put up your sword, for every one that takes the sword shall perish with the sword.”
Ambrose’s mention of “love toward neighbor,” as a paradigm for how one treats an assailant is crucial. For Ambrose, love of neighbor translates into an obligation to preserve the life of a neighbor, even when that neighbor is an assailant. If someone privileges their own life over another, even an attacker, they are guilty of not loving their neighbor.
“Why do you consider yourself greater than another, when a Christian man ought to put others before himself, to claim nothing for himself, usurp no honours, claim no reward for his merits? . . . . A virtuous and a shameful life cannot go together, since they are absolutely severed by the law of nature” 
Ambrose is explicit that the equality of all humans before God implies that the Christian cannot privilege his or her own life above any one else’s, not even an enemy. To do anything else is shameful and un-virtuous.
Love is Risky
Ambrose’s thought on conflict and peace exemplifies the tension between realism and Christianity’s idealistic antipathy toward violence. Although Ambrose allows for certain spheres of permissible violence, he finds himself returning to these central dictates of the Gospel as the Church’s primary identity: To love thy sinful neighbor, even at risk of your own safety. The faith that worships a God who loved his enemies even unto execution, demands a constant resuscitation of this central conviction. God has deemed all life worth preserving, even sinful life. In fact, in God’s economy there is no distinction between innocent and guilty. All lives are equally valuable to God. Love thy sinful neighbor, even at risk of your own safety. Click To Tweet
Ambrose reminds us well: God loves all people equally, and we are called to do the same. This central conviction prevents us from finding any easy answers to questions of guns, war, and self-defense. However Christians ultimately settle on these particular issues, we are compelled to constantly return to peace and non-violence as central Christian values that lie at the heart of the Gospel message of a compassionate and self-giving God. These convictions should be protected, and privileged highly, as we make moral judgments; as Ambrose does.
Some of this material originally appeared at AfterLunchTheism.Wordpress.com.  George Kalantzis, Caesar and the Lamb: Early Christian Attitudes on War and Military Service (Wipf & Stock, 2012).  Kalantzis, 53, emphasis mine.  Lois J. Swift, “St. Ambrose on Violence and War,” Transactions and Proceedings of the American Philological Association, Vol. 101 (1970), p. 534.  De Officiis, 1.35.177  Swift, 537.  Ambrose, Epistle 60, Fathers of the Church.  De Officiis 1.35.175 as quoted in Swift, 537.  De Officiis, 3.