“May the Queen of Peace save the world from the madness of war,” Pope Francis wrote in his call for fasting.

The ancient Christian practice of fasting allows believers to heighten their senses and focus their spiritual energies, said Mark Morozowich, a theologian at the Catholic University of America. He said Ukrainian Catholics like him started Lent on Monday, unlike Roman Catholics who start on Wednesday, but different groups of Christians will be engaged in similar spiritual acts during the Lenten period.

“The world is being called to deeper prayer,” said Morozowich, who is dean of CU’s School of Theology and Religious Studies. “As we continue to stand with our Ukrainian brothers and sisters, and as the world shows the Russian authorities that this is intolerable, we have the opportunity to … try to build a world based on mutual respect and order, and not on the basis of tyranny and fear, which is built on respect and love for our fellow human beings.

For Christians observing Lent, including President Biden who is Catholic, Ash Wednesday marks the start of the period of weeks leading up to Easter Sunday, which most Christians in the United States will celebrate on April 17.. The weeks of Lent serve as a time to reflect on the biblical story of Jesus’ time in the desert, where he fasted and prayed before his death and resurrection.

Although most Americans celebrating Lent will begin on Wednesday, the majority of people living in Russia and Ukraine belong to the Orthodox Christian wings of Christianity, most of which will begin Lent on March 7 and end on the day they celebrate Easter. April 24.

During Lent, many Catholics and some Protestants give up something during the period and practice forms of fasting, such as abstaining from meat. Many groups are holding prayer services specifically on behalf of Ukrainians this year. For example, on Wednesday, the Catholic University’s Center for Ukrainian Church Studies will hold a day-long prayer vigil in the Basilica of the Byzantine Chapel at the National Shrine in Washington.

Although fasting is not obligatory for Ukrainian Catholics as it is for Roman Catholics, Robert Hitchens, pastor of the Holy Family Ukrainian Catholic Shrine in northeast Washington, DC, said he encouraged his congregation to participate in the global fast on Wednesday.

“Everyone is excited and on pins and needles,” Hitchens said of members of his congregation. “With Lent coming, it is a time to pray intensely and do good works. It’s a way for people to actually do something.

Other Christian leaders have also called for Ash Wednesday prayers on behalf of Ukrainians. Five Christian world communions — including the World Communion of Reformed Churches, the The Lutheran World Federation and the Mennonite World Conference – will hold a joint prayer service on Ash Wednesday for peace in Ukraine.

And several people said they plan to fast on Wednesdays even if they don’t belong to the Roman Catholic Church. Dan Gibson, who is part of the Anglican Church of North America and would not generally follow the direction of Pope Francis, said he felt the Ash Wednesday fast was an ecumenical time for Christians around the world after seeing Archbishop of Canterbury Justin Welby, the spiritual leader of Anglicans around the world, join Francis’ call.

“I am a lawyer, not a soldier, not an ambulance driver. I’m not a person who can go to Ukraine and do a lot to help anybody,” said Gibson, who lives in Durham, North Carolina. “As a Christian, I believe that God hears our prayers. At least that’s something I can do.

Although she left the Catholic Church of her youth, Patricia Yingst, who now describes herself as spiritual, saw Pope Francis’ call to fast and is considering joining him.

“I wish I could hug a Ukrainian right now. All I can do is meditate and pray right now,” said Yingst, who is based in Oroville, Calif. I know what I can do to support people who are trying to make a difference. It seems like a small thing, but I’m doing what I can.

Hoping to show solidarity with the people of Ukraine, Jared Cook said that while his denomination, The Church of Jesus Christ of Latter-day Saints, does not observe Lent or Ash Wednesday, he plans to join to others who fast.

LDS members generally fast for one Sunday each month and are asked to donate the money they would have spent on food to the LDS Church, which then distributes it to those in need. Cook said he felt he didn’t need to wait for LDS leaders to call for a fast for Ukrainians.

“Scrolling through Twitter, watching updates of what’s happening in Ukraine, your heart goes out to these people, seeing how they’re defending themselves,” said Cook, who is an attorney in Rochester, NY. “There’s a feeling of helplessness that comes with that. It’s not like I can show up in person, pick up a gun and help them.

Christians have historically fasted for all sorts of reasons, and Ash Wednesday reminds people of their own mortality and lack of control, said Tyler Wigg-Stevenson, a Toronto Anglican priest who has campaigned against the use of nuclear weapons.

“It’s interesting to think that people cling to fasting as a way to give them agency,” he said. “But that’s the spiritual movement that Christians have always done. Here is this war that we cannot control, but we will recognize our dependence on a higher power.

In the biblical story of Jonah, when the prophet warned Nineveh of impending destruction because of his wickedness, the city turned to fasting and prayer, and God decided not to destroy the city. Fasting breeds weakness, Wigg-Stevenson said, and it shows how dependent and vulnerable people are.

“When you think of fasting, especially toward an end rather than for self-improvement, it is not about your own agency but about an acknowledgment of your dependence on God. We fast and repent because it’s our way of getting closer to the reality of death,” he said. “After fasting, you desperately need food. It’s a way of appealing to the hope of life who overcomes death. It seems appropriate to do so in the face of war. We appeal to the Lord of life, to him who can offer resurrection in the face of death.