“We were speaking out against omnicide⁠—the destruction of all life,” the anti-nuclear weapons activist Dean Hammer said before a court in Norristown, Pa., in 1990. A decade before, Mr. Hammer and seven other Christian activists, known as the Plowshares Eight, trespassed onto a General Electric facility in King of Prussia, Pa., where they vandalized nuclear warheads in a nonviolent direct action. The eight, which included the prominent peace activists Daniel Berrigan, S.J., and his brother, Philip Berrigan, took seriously the command of the Prophet Isaiah: “And they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore” (2:4).

The protest at General Electric inaugurated the Plowshares movement, which for nearly four decades has led several dozen nonviolent actions in opposition to nuclear proliferation and the ever-present threat of war. On April 4, 2018, the 50th anniversary of the assassination of Martin Luther King Jr., seven Plowshares activists illegally entered the naval submarine base in Kings Bay, Ga., staining the property with their blood and placing crime scene tape around the base. Now they are facing up to 25 years in prison.

The $1.3 billion, 9,000-personnel base is home to several ballistic missile submarines and includes the Trident Training Facility, where sailors are taught how to operate the missiles.

On April 4, 2018, seven Plowshares activists illegally entered the naval submarine base in Kings Bay, Ga., staining the property with their blood.

In a joint statement, the Plowshare activists—Martha Hennessy, Elizabeth McAlister, Clare Grady, Patrick O’Neill, Carmen Trotta, Mark Colville and Steve Kelly, S.J.—said, “Nuclear weapons eviscerate the rule of law, enforce white supremacy, perpetuate endless war…and ensure impunity for all manner of crimes against humanity.” The group also called on the Catholic Church to take action: “We plead to our Church to withdraw its complicity in violence and war.”

Many church leaders, peace activists and theologians have voiced their support for the Kings Bay Plowshare activists. An international petition to dismiss the charges against the activists includes the Nobel Peace Prize laureate Mairead Maguire, Bishop John Stowe of Lexington, Ky., and Archbishop Emeritus Desmond Tutu of Cape Town, South Africa, among its signatories.

In advance of the Plowshares’ trial on Oct. 21, America spoke with two theologians—Jeannine Hill Fletcher of Fordham University and Harold W. Attridge of Yale Divinity School—to discuss where nonviolent opposition to nuclear weapons fits within the Catholic tradition.

“These folk were making a prophetic statement in line with Catholic teaching and in line with the Gospel message,” said Mr. Attridge, the Sterling Professor of Divinity at Yale Divinity School.

“These folk were making a prophetic statement in line with Catholic teaching and in line with the Gospel message,” said Mr. Attridge.

Mr. Attridge considers nonviolence “a fundamental value of the Gospel message” that has been put into practice by Christians like Martin Luther King Jr. and the Berrigan brothers.

“At the heart of the Gospel message, you have [the] sayings of Jesus, things like the Sermon on the Mount, to turn the other cheek. That is, to not respond violently,” he said.

Ms. Fletcher, a professor of theology at Fordham, also sees the essential continuity between the anti-nuclear protest and Catholic teaching. “What I saw in the Plowshares action is a commitment to the Catholic tradition where the primacy of conscience, all the way back to Aquinas, [says] we should not be following unjust laws—human laws that break and go against the moral law,” she said.

After meeting Mr. Trotta and Ms. Hennessy, the granddaughter of Servant of God Dorothy Day, at the Catholic Worker in New York City, Ms. Fletcher was asked to testify in defense of the Plowshares activists.

In the pending legal case against the Plowshares, Ms. Fletcher said, the fundamental question is, “Is this action grounded in a deeply held religious belief?”

“I was asked to provide evidence that would support their petition for dismissal of the charges or reduction of the charges based on whether…the court would be able to see their action as aligned with the principles of the Restoration of Religious Freedom Act,” she said.

The Restoration of Religious Freedom Act of 1993 states that “governments should not substantially burden religious exercise without compelling justification.” Any action by the government that would infringe upon religious freedom therefore faces “strict scrutiny.”

In the pending legal case against the Plowshares, Ms. Fletcher said, the fundamental question is, “Is this action grounded in a deeply held religious belief?”

While the individual histories and written statement of the Plowshares certainly reveal a depth of faith, the movement’s methods, including breaking the law and the pouring of blood, remain a point of contention for some.

In an article in the journal U.S. Catholic Historian in 2009, titled, “Disruptive Action and the Prophetic Tradition: War Resistance in the Plowshares Movement,” the sociologist Sharon Erickson Nepstad notes mixed reactions, even among Catholics like Dorothy Day and Thomas Merton, to the illegal burning of draft files by the Catonsville Nine in May 1968. “Although there was little agreement within the Catholic peace movement about the legitimacy of this tactic, it stirred significant debate and dialogue,” writes Ms. Nepstad. She further references how opposition to Plowshares actions in the past have stemmed from a concern that such methods “could backfire by alienating potential sympathizers.”

Ms. Fletcher refers to the Plowshares’ protest at Kings Bay as “a sacramental action,” in which blood functioned to bless a space profaned by nuclear arms.

“There’s going to be a difference of opinion among Christians on how a prophetic ministry ought to be conducted,” said Mr. Attridge. “It’s one thing to say, ‘Oh, let’s not confront violence with violence.’ It’s another thing to say let’s take a stand against the structures that support and foster violence. And nuclear weapons certainly are structures that support and foster violence in a major way.”

Ms. Fletcher refers to the Plowshares’ protest at Kings Bay as “a sacramental action,” in which blood functioned to bless a space profaned by nuclear arms.

When asked about those who might take offense at the tactics of the activists, she responded: “You’re scandalized by the sprinkling of blood. How come you’re not scandalized by the potential of these bombs to actually spill blood around the globe?”

Like Mr. Attridge, Ms. Fletcher also sees a prophetic character in the Plowshares’ protest, calling it “public” and “over the top,” akin to the ministry of prophets in the Hebrew Bible. She points to the writings of Rabbi Abraham Joshua Heschel, who understood the biblical prophets as not exclusively clairvoyants or soothsayers but as disruptive instruments of God. “The prophet’s task is to convey a divine view, yet as a person he is a point of view,” Rabbi Heschel wrote in his 1962 book The Prophets.

“I want to witness to justice and peace, and I want that to be a gift to my offspring but also to all our offspring,” McAlister said.

In the face of possible imprisonment, the Plowshares have not stopped their ministry. On Sept. 29, all of the Kings Bay activists except Father Kelly and Mr. Colville attended a Festival of Hope at the Holyrood Episcopal Church in Washington Heights in New York City. The afternoon gathering gave over 250 supporters, including the journalist Amy Goodman and the Grammy-winning singer-songwriter Tom Chapin, an opportunity to hear directly from the activists. A banner at the front of the altar announced its cause: “For A Nuclear Weapon Free World.”

Bud Courtney, who lives at the St. Joseph House Catholic Worker in Manhattan’s East Village, read aloud a letter from Father Kelly, while Mr. Colville called into the celebration from jail, where he has been awaiting trial since his arrest in April 2018. (He was released Oct. 1 on bond.)

“What am I doing here?” said Mr. Colville via phone to the congregation. It is a question Mr. Colville has asked himself many times since his arrest. “I think it’s particularly a relevant question in the weeks ahead when we go into the courtroom,” he said. Ms. Hennessy made a similar comment of uncertainty coupled with great conviction. “I still don’t know if I’m prepared to continue in this effort, but here I am,” she said.

Ms. McAlister, the wife of the late Philip Berrigan, said she was inspired to take part in yet another Plowshares action because she “wanted [her] life to have some sense of meaning.”

“I want to witness to justice and peace, and I want that to be a gift to my offspring but also to all our offspring,” she said.

The Rev. Luis Barrios, the pastor of Holyrood, paraphrased this June 1963 quotation by Martin Luther King Jr. in Detroit: “And I submit to you that if a man has not discovered something that he will die for, he isn’t fit to live.”

This is how Ms. Fletcher understands the actions of the Plowshares. “It seemed to me, as a theologian, that if we’re looking for work in the world that is carrying out this vision of blood being meant for life, that the Plowshares were willing to do that work—with their own blood, with their own lives,” she said.

Jury selection for the trial of the Kings Bay Plowshares begins at 9 a.m. on Oct. 21 in Brunswick, Ga.

Ryan Di Corpo previously served as the managing editor of Outreach and was also a former Joseph A. O’Hare, S.J., Fellow at America.