ROME— Surrounded by leaders of the world’s major religions, including Jews, Buddhists, Muslims, Hindus, Sikhs, followers of traditional faiths and even atheists, as well as survivors of war and migrants, Pope Francis declared Tuesday that the “great sickness” of our time is “indifference” to human suffering.

The pontiff was in the birthplace of St. Francis, his namesake, for an interfaith summit marking the 30th anniversary of an historic assembly of religious leaders convened by St. Pope John Paul II at the height of the Cold War.

Joining fellow Christian leaders in prayer, Francis said that millions around the globe today are victims of war and are pleading for peace, often receiving nothing but the “bitter vinegar of rejection,” their cries silenced “with the same ease with which television channels are changed.”

He delivered two sets of remarks on Tuesday, first a meditation for the Christian leaders, and then a short speech for all the leaders gathered.

In the latter, he said that indifference to suffering which is a product of war is a virus “that paralyzes, rendering us lethargic and insensitive, a disease that eats away at the very heart of religious fervor, giving rise to a new and deeply sad paganism: the paganism of indifference.”

The families whose lives have been shattered by war, the children who’ve known nothing but violence, the elderly who’ve been forced to abandon their countries, all of them, Francis said on Tuesday closing the World Day of Prayer for Peace, “have a great thirst for peace.”

Appealing to the world’s religious followers, the pontiff called for these tragedies not to be forgotten, and for their leaders gathered in Assisi to become the voice of all those who suffer and whose voices aren’t heard.

“We do not have weapons,” Francis said of the religious leaders. “We believe, however, in the meek and humble strength of prayer.”

The pontiff suggested that “thirst for peace” became a prayer to God on Tuesday in Assisi, so that “wars, terrorism and violence may end.”

That peace is neither a protest against conflict nor, as St. John Paul II said back in 1986, in the first of these interreligious gatherings, is it “a result of negotiations, political compromises or economic bargaining. It is the result of prayer.”

The peace Francis prayed for is one rooted in God, not in pride, personal interests, profit at any cost, or the arms trade.

It’s a “true peace that is not illusory,” hence not the result of avoiding difficulties, nor the cynicism of one who “washes his hands of any problem that is not his,” or of who takes a “virtual approach” judging things through a computer keyboard.

Peace, he said, has to be built by giving “first place” to those who suffer, fixing conflicts from within, through a consistent goodness and rejecting the “shortcuts offered by evil.”

And believers, regardless of their faith, are called to be “artisans of peace.”

According to Francis, peace means forgiveness; welcome and openness to dialogue; cooperation, and education, which he described as a call to learn “the challenging art of communion.”

Earlier in the day, at the Lower Basilica of St. Francis, the pontiff participated in an ecumenical prayer with the Christian leaders who had traveled to Assisi to participate in the 30th World Day of Prayer for Peace.

Among those gathered were three with whom Francis had private meetings before the prayer: The Ecumenical Patriarch of Constantinople, Bartholomew I; His Holiness Ignatius Aphrem II of Antioch, Patriarch of the Syriac Orthodox Church; and Canterbury’s Archbishop Justin Welby, head of the Church of England.

In parallel, leaders of other religions prayed in different locations across the city, each according to their own beliefs, practices and rites.

During the ecumenical Christian prayer, countries where war is waged today, such as Syria, Iraq, Afghanistan, Central African Republic, Nigeria, Central America, the Democratic Republic of Congo, and the drug trade in Mexico, were named one by one and a candle lit. Priests and bishops who’ve been kidnapped, and have yet to be found, were also included in the prayer intentions.

Before an image of the crucified Christ, Francis said in his meditation during the prayer, Christians are called to “contemplate the mystery of Love not loved and to pour out mercy upon the world.”

Calling Jesus’s cross the “tree of life” with which “evil was transformed into good,” the pontiff said that Christians too are called to be trees of life that “absorb the contamination of indifference and restore the pure air of love to the world.”

“The victims of war, which sullies people with hate and the earth with arms, plead for peace; our brothers and sisters, who live under the threat of bombs and are forced to leave their homes into the unknown, stripped of everything, plead for peace,” Francis said.

These people, he continued, are the “wounded and parched members of [Jesus’s] body,” and like him, are often given the “bitter vinegar of rejection.”

“Who listens to them? Who bothers responding to them? Far too often they encounter the deafening silence of indifference, the selfishness of those annoyed at being pestered, the coldness of those who silence their cry for help with the same ease with which television channels are changed,” he said.

The first one to speak during the ecumenical prayer was Welby, who regretted that the “greatest wealth in European history has ended in the tragedies of death and slavery.”

Modern economies, he said, can spend so much, yet are built on merely sandy foundations.

“Despite it all, we find dissatisfaction and despair, in the breakdown of families, in hunger and inequality,” Welby said, “in people who turn to extremism.”

God instead, in his mercy reaches to “each for each and all of us,” offering a “wealth that is real and that will bring satisfaction.”

Pope Francis made the trip to Assisi to close the three-day event (Sept. 18-20), convened under the lemma “Thirst for Peace: Religions and Cultures in Dialogue.” The encounter is organized yearly by the Sant’Egidio Community, this time together with the Franciscan Families and the Diocese of Assisi.

The pontiff arrived in the Italian city by helicopter in the late morning, where he greeted the participants one by one. Many of them had lunch together at the Franciscan convent: Ravioli with ricotta cheese and spinach, turkey with beans and a fruit-pie pastry.

Among the VIP guests for the lunch was a group of victims of war and some refugees who have arrived in Italy through a humanitarian corridor put together by Sant’Egidio.

The interreligious prayer held this week in Assisi was first organized under St. John Paul II back in 1986. Although they’ve been held annually since then, it’s the fifth time a pontiff has participated. The Polish pope convened twice more, and Benedict XVI once.

Throughout the three days, more than 30 panels were held by the different faith communities, discussing conflict and other concerns in various parts of the world: how to combat violence and extremism, how to educate future generations for peace, caring for the environment, how to work more closely together to fight poverty and oppression.

As he often does when he wants to strengthen a point he was to make, in his closing remarks, Francis quoted two of his predecessors.

Reiterating John Paul’s words from 2002, he said that once again, religious leaders had gathered to “declare that whoever uses religion to foment violence contradicts religion’s deepest and truest inspiration.”

“We further declare that violence in all its forms does not represent ‘the true nature of religion. It is the antithesis of religion and contributes to its destruction,’” he said, quoting from the 2011 address of his immediate predecessor, Benedict XVI.

“We never tire of repeating that the name of God cannot be used to justify violence. Peace alone, and not war, is holy!” Francis said.

Saying that peace is a “workshop,” he concluded his remarks calling on religious leaders to assume the responsibility of building peace, “reaffirming today our ‘yes’ to being, together, builders of the peace that God wishes for us and for which humanity thirsts.”

The closing ceremony also included the witness of Tamar Mikadi, a Syrian refugee who fled the “martyred city” of Aleppo, Syria, with the help of Sant’Egidio’s humanitarian corridor.

Talking about her city, she said, “breaks my heart,” since it was there that she was born, raised and where she got married. She and her family lasted three years in Syria after the war broke out, and then lived as refugees in Lebanon for two more years before emigrating to Italy four months ago.

“I remember my many Muslim and Christian friends,” she said. “Now, distinctions are made between Muslims and Christians, but before the war there was no difference, everyone practiced his or her religion, in a land formed by a mosaic of different cultures and religions. Then the war broke out. And I still don’t really know why.”

Mikadi spoke of remembering missiles pouring down in her city destroying houses, and about hearing the screams of mothers, fathers and desperate children, and of everyone praying together.

“To all of you, men and women of religion, and to you, your Holiness, on behalf of the Syrian people, we ask for a prayer of peace and love, to return to Syria. And to the rest of the world, thank you,” she said.

At the end of the ceremony, representatives of each religion present signed an appeal for peace, urging leaders of nations to defuse the causes of war, “the lust for power and money, the greed of arms’ dealers, personal interests and vendettas for past wrongs,” and the underlying causes of conflicts, including “poverty, injustice and inequality, the exploitation of and contempt for human life.”