ROME—Ahead of his day trip to Assisi to participate in a World Day of Prayer for Peace, Pope Francis said that the gathering of women and men religious from around the world is not a “spectacle” but simply a prayer for peace in a world at war.

“Today the world will have its center at Assisi, for a day of prayer, penitence and crying, because the world is at war,” he said on Tuesday. “God the father of all, Christians and not, wants peace. There’s no god of war, this is done by the devil.”

War, he said, including the inhumanity of a bomb that explodes killing and wounding, cutting off the path of humanitarian aid that can reach children, the elderly and the sick, he said, is the work “of the evil one” who wants to “kill everyone.”

Although according to the report of Vatican Radio the pope didn’t mention it, the allusion to “humanitarian aid” could have been a reference to a convoy headed to the war-torn city of Aleppo, in Syria, which was bombed on Monday, leaving 12 killed.

Speaking at his morning Mass only hours before taking the helicopter ride to the small Italian city, birthplace of St. Francis and where Pope John Paul II first organized these interreligious gatherings to pray for peace 30 years ago, the pontiff also said he’d sent letters to all the bishops of the world, urging them to lead their dioceses in prayer.

“We pray to the Lord, so that he gives us a heart of peace, beyond religious differences, because we are all children of God,” Francis said. “It’s necessary to pray, even to cry for peace, with all the faithful united in the conviction that God is a God of peace.”

St. John Paul II closed that first meeting in 1986 with a call to continue spreading the message of peace and living “the spirit of Assisi.”

Since then, the community of Sant’Egidio, a new movement in the Catholic Church, has sought to fulfill that message by convening an annual meeting of religious leaders to discuss critical global issues of peace, unity, and interreligious dialogue.

On Tuesday, the pope will close what was a three day gathering of over 500 religious leaders from nine religions, including Buddhism, Islam, Judaism, several Christian denominations, and atheists.

Also taking part will be a group of immigrants; politicians, such as Italian president Sergio Matarella; cultural leaders, such as the Peace Nobel Prize winners Tunisia’s quartet; survivors of the Holocaust, and victims of ongoing wars.

The message of this unique encounter is clear: religion cannot be used as an excuse for violence.

Presenting the gathering last week, Assisi’s Bishop Domenico Sorrentino said that thirty years ago the world was marked by the Cold War, with peace defended by opposing nuclear arsenals.

“Today, we find what Pope Francis realistically defined as Third World War in pieces,” Sorrentino said at a press conference. “It’s hard to understand where our world is going.”

The Argentine pontiff has often spoken of a “piecemeal war,” with ongoing conflicts across the planet, several with no definitive resolution in sight.

Afghanistan, Syria, Iraq, and Nigeria all have at least 10,000 casualties in the last year.

Francis has also said there’s no such thing as a religious war going on in the world, and that killing in the name of God is, in fact, killing in the name of the devil.

However, in the last three conflicts mentioned above, religious minorities such as Christians and Yazidis are suffering in the hands of so called Islamic fundamentalists, with groups such as ISIS and Boko Haram.

The United States and many other key players in the international community have already declared that what’s going on in Syria and Iraq is in fact, genocide, which makes the Spirit of Assisi all the more urgent.

In Assisi, Francis was scheduled to have private meetings with several leaders, have lunch, participate in an ecumenical prayer and address the crowd in the Roman afternoon.