KRAKOW, Poland — Addressing more than a million young women and men who’d walked almost nine miles to participate in a prayer vigil, Pope Francis called on youth not to be “couch potatoes.”

“The times we live in do not call for young ‘couch potatoes’ but for young people with shoes, or better, boots laced. It only takes players on the first string, and it has no room for bench-warmers,” Francis said.

Talking to young people on Saturday night in Krakow, Poland, where they’ve been participating in a week-long rally called World Youth Day, Francis warned them against the “sofa-happiness,” calling it the most “harmful and insidious form of paralysis.”

A sofa, he said, that “makes us feel comfortable, calm, safe,” away from any kind of pain or fear, spending hours playing video games or in front of a computer screen.

He said it’s a dangerous paralysis because as “we start to nod off” other people, “more alert” but “not necessarily better, decide our future for us.”

For many people, Francis warned, it’s better to have drowsy, tone-deaf and dull kids who confuse happiness with a sofa.

“For many people, that is more convenient than having young people who are alert and searching, trying to respond to God’s dream and to all the restlessness present in the human heart,” the pope said, adding that they hadn’t come into this world to “vegetate, to take it easy” but to “leave a mark.”

“But when we opt for ease and convenience, for confusing happiness with consumption, then we end up paying a high price indeed: we lose our freedom,” Francis said.

Following Jesus, the pope continued, demands courage and a readiness to change the couch for walking shoes.

“[God] is encouraging you to dream. He wants to make you see that, with you, the world can be different. For the fact is, unless you offer the best of yourselves, the world will never be different,” Francis said.

Throughout the day, young pilgrims staying in Krakow and in cities surrounding it to participate in World Youth Day (WYD) trekked on foot to arrive at Campus Misericordiae, a field prepared for the occasion on the outskirts of Krakow.

Many made the hike carrying backpacks and sleeping bags, since they’ll spend the night in the field. Along the way, hundreds of Polish people came out from their homes to give them fresh water and, in some cases, even to hose them down to help them keep cool.

At Campus Misericordiae, on a 100-yard-long altar area where the final Mass will be celebrated Sunday morning, Francis led them in prayer, but before and after him, several dozen artists from around the world kept the flow going.

During the night, after the pope left the field, chapels for adoration were set to be open all night and priests available for confession in many designated areas.

“Today’s world demands that you be a protagonist of history, because life is always beautiful when we choose to live it fully, when we choose to leave a mark,” a visibly animated Francis said, responding to the questions posed to him by three youth before the Eucharistic adoration began.

The pontiff was visibly moved by the experience of Rand Mittri, a 26-year-old Syrian from Aleppo, who told the pope and the millions attentively listening to her that her city has been destroyed, and “the meaning of our lives has been cancelled. We are the forgotten.”

Attempting to “share a few aspects of our reality” with those participating in the event, Mittri spoke about the fear that overcomes her when she leaves her home every morning, because she knows it’s possible that when she comes back from work, her family might not be there.

“Perhaps we will be killed that day. Or perhaps our family will,” she said.

“It is a hard and painful feeling to know that you are surrounded by death and killing, and there is no way to escape; no one to help,” Mittri said, visibly emotional, before an audience that was equally tearing up.

This young woman shared her personal experience with the ongoing Syrian war, which began five years ago and has caused the death of 400,000 people, and which does not seem to be coming to an end any time soon.

The conflict, she said, has caused her to grow up ahead of time and to see things differently.

Mittri works at a Don Bosco Center in Aleppo, which daily receives more than 700 young men and women who “come hoping to see a smile,” and seeking something lacking in their lives – she called it “humanitarian treatment.”

“But it is very difficult for me to give joy and faith to others, while I myself am bankrupt of these things in my life,” Mittri said.

“Through my meager life experience, I have learned that my faith in Christ supersedes the circumstances of life. This truth is not conditioned on living a life of peace that is free of hardship. More and more, I believe that God exists despite all of our pain,” she said.

Pope Francis began his remarks talking about Mittri, who was the second of the three who shared their lives with the crowd. He talked about where the pilgrims who took part in WYD come from: from countries at conflict and war, or from countries “at peace” where most terrible things are stories on the evening news.

“For us, here, today, coming from different parts of the world, the suffering and the wars that many young people experience for us are no longer anonymous, something we read about in the papers. They have a name, they have a face, they have a story, they are close at hand,” Francis said.

Throughout the week, Christians who are victims of persecution around the world had a special place at World Youth Day, with Archbishop Bashar Warda of Iraq addressing over 20,000 English-speaking pilgrims at the Mercy Center, the largest catechesis spot in Krakow, sponsored by the Knights of Columbus.

Warda came to Poland with 200 pilgrims from his country, some of whom carried the cross during the Way of the Cross prayer on Friday.

Saturday’s vigil was the eve of the closing of a week-long celebration and affirmation of the Catholic faith. Young people from around the globe gathered in the city of St. John Paul II to share their experiences, to pray together and to get to know the reality of Christians living in different places.

For one week, no border divided Americans from Mexicans, Middle Easterners from Europeans, Ukrainians from Russians. For one week, the remainder of what unites them was more important than that which divides them.

As the pope put it, situations that would typically seem distant, “because we see them on the screen of a cell phone or a computer,” became a reality for many.

Getting involved, Francis said, is not about “denouncing anyone or fighting” because “we have no desire to conquer hatred with more hatred, violence with more violence, terror with more terror.”

“Our response to a world at war has a name: its name is fraternity, its name is brotherhood, its name is communion, its name is family,” the pope said.

“Let our best word, our best argument, be our unity in prayer,” Francis said.

Close to the end of his remarks, the pontiff encouraged the youth to take the path of the “craziness” of God, “who teaches us to encounter him in the hungry, the thirsty, the naked, the sick, the friend in trouble, the prisoner, the refugee and the migrant, and our neighbors who feel abandoned.”

God, he told them, encourages the young to be politicians, thinkers, social activists, and promoters of an economy inspired by solidarity.

Amid all the seriousness during these days, with Francis’ visit to the infamous Auschwitz-Birkenau concentration camp and often talking about some of today’s dramas such as war, terrorism and migration, the pope nevertheless found moments on Saturday to let it all hang out.

For instance, earlier in the day, he had lunch with 14 youngsters, including one from Brazil. Known for his love for soccer, Francis asked the young man who’s better, Argentina’s famous soccer player Maradona or Brazil’s Pele. To which he answered that, “as a Brazilian” it’s another Argentinian, Lionel Messi.

He had a similar relaxed moment at the beginning of the vigil. He was scheduled to go through a Holy Door accompanied by six young people. After doing so, he unexpectedly invited them to join him on the Popemobile, took them for a spin and then asked them to sit next to him on stage.

Towards the end of his remarks on Saturday’s vigil, Francis said that nowadays it’s easier to concentrate on divisions, and asked everyone on the Campus Misericordiae to hold hands, building a “great fraternal bridge.”

“People try to make us believe that being closed in on ourselves is the best way to keep safe from harm. Today, we adults need you to teach us how to live in diversity, in dialogue, to experience multiculturalism not as a threat but an opportunity,” the pope said.