For its first three centuries, Christianity required the practice of active non­violence as taught by Jesus. Early Christians refused to serve in Rome’s armies or kill in its wars. All that changed in the year 313, when Emperor Constantine legalized Christianity, and established it as the official religion of the empire. In effect, he threw out the commandment to love one’s enemies and turned to the pagan Cicero to justify Christian violence, sowing the seeds for the so-called just war theory.

During the seventeen centuries since, Christians have waged war, led crusades, burned women at the stake, persecuted Jews and Muslims, kept slaves, run concentration camps, prayed for successful bombing raids, and built and used nuclear weapons. Jesus’ teachings of nonviolence have rarely been discussed, much less implemented. Even as recent popes have proclaimed a “Gospel of Life,” they’ve made exceptions, leaving loopholes for justified killing.

That may be about to change. In April 2016, eighty prominent Catholic peacemakers from twenty-five nations were invited to the Vatican for a conference to discuss formally abandoning the just war theory. The event was hosted by the Pontifical Council for Justice and Peace. Cardinal Peter Turkson, the leader behind Pope Francis’s recent encyclical on the environment, opened the conference by reading a long letter of welcome from Pope Francis. Cardinal Turkson participated in the conference and approved the closing statement, which was then presented to the pope.

For three days, we deliberated about questions of violence, war, and nonviolence. Many attendees shared personal experiences practicing nonviolence, often in warzones. I was asked to speak about Jesus and nonviolence. That’s easy, I said: Jesus did not teach us how to kill or wage war or make money; he taught us how to be nonviolent. In the Sermon on the Mount he says: “Blessed are the peacemakers, they are the sons and daughters of God. ... You have heard it said, thou shall not kill; I say to you, do not even get angry. ... You have heard it said, an eye for an eye; but I say to you, offer no violent resistance to one who does evil. ... Love your enemies.” Nowhere does he say: “ ...but if your enemies are really bad, and you meet these seven conditions, kill them.” There is no just war theory, there are no exceptions.

During the closing hours we debated, approved, and released a statement calling on Pope Francis to write an encyclical that would formally reject the just war theory once and for all and return the Church to the nonviolence of Jesus. The statement offers four points: that Jesus was nonviolent; that there is no just war; that nonviolence works; and that the time has come for the Church to apply and teach nonviolence at every level around the world. To quote some highlights:

We live in a time of tremendous suffering, widespread trauma and fear linked to militarization, economic injustice, climate change, and a myriad of other specific forms of violence. In this context of normalized and systemic violence, those of us who stand in the Christian tradition are called to recognize the centrality of active nonviolence to the vision and message of Jesus; to the life and practice of the Catholic Church; and to our long-term vocation of healing and reconciling both people and the planet. ...

The time has come for our church to be a living witness and to invest far greater human and financial resources in promoting a spirituality and practice of active nonviolence and in forming and training our Catholic communities in effective nonviolent practices. In all of this, Jesus is our inspiration and model.

In his own times, rife with structural violence, Jesus proclaimed a new, nonviolent order rooted in the unconditional love of God. ... Neither passive nor weak, Jesus’ nonviolence was the power of love in action. In vision and deed, he is the revelation and embodiment of the nonviolent God, a truth especially illuminated in the cross and resurrection. He calls us to develop the virtue of nonviolent peacemaking.

Clearly, the Word of God, the witness of Jesus, should never be used to justify violence, injustice, or war. We confess that the people of God have betrayed this central message of the gospel many times, by participating in wars, persecution, oppression, exploitation, and discrimination.

We believe that there is no just war. Too often the just war theory has been used to endorse rather than prevent or limit war. Suggesting that a just war is possible also undermines the moral imperative to develop tools and capacities for nonviolent transformation of conflict. We need a new framework that is consistent with gospel nonviolence. ...

 “The death of a single human is too heavy a price to pay for the vindication of any principle, however sacred.” Daniel Berrigan

Among other points, the statement specifically challenges the church to develop its social teaching on nonviolence; to promote nonviolent practices such as restorative justice, trauma healing, and unarmed civilian protection; to no longer use or teach just war theory; to continue advocating for the abolition of war and nuclear weapons; and to support and defend nonviolent activists whose work for peace and justice puts their lives at risk. I encourage you to read the full statement at nonviolencejustpeace.net.

If it heeds this call, the Catholic Church could change course from the last seventeen hundred years, opening up a whole new history for Christianity and returning us to the spirit of the early church, where no Christian was allowed to participate in war, prepare for war, or kill another human being. If Pope Francis writes such an encyclical, it could have an impact far beyond the world’s one billion Catholics. He could help us all better understand how war has become obsolete, how nonviolence offers far better prospects for conflict resolution, and why the time has come to abolish war and nuclear weapons.

Also read John Dear’s Remembrance of Daniel Berrigan.