He spoke from the balcony of the Bishop's Palace, telling the thousands of youth gathered below not to be afraid, but to have faith and spread the joy that comes from following Christ.
Pope Francis is currently in Krakow for this July 27-31 trip to Poland for WYD. Every night when he comes back to the city after the day's activities, Francis is set to appear on the palace balcony to address youth gathered below.
The tradition was initiated by St. John Paul II, who spoke to youth from the balcony every time he visited his homeland as Pope. It was continued by Benedict XVI when he visited Poland in 2006, and is now being carried on by Francis.
In his brief speech, the Pope first recalled the story of a young man who had studied graphic design for just over two years, but decided to leave his studies in order to volunteer for WYD.
He immediately put his talents to use, designing all of the banners that currently decorate the streets of Krakow in honor of WYD, the Pope said, noting that "images of the patron saints" found on practically every street - St. John Paul II and St. Maria Faustina Kowalska - were done by this young man.
In the process of his work for WYD, the youth rediscovered his faith, but was diagnosed with cancer in November, Pope Francis recalled. He noted how the doctors had amputated the young man's leg in an effort to save his life, but it didn't work, and the cancer continued to spread.
This young man "wanted to live through the Pope's visit" and had even reserved a place on the Krakow tram that the Pope will take later in the week with sick and disabled youth as his special passengers. However, the young man didn't make it, and died July 2.
"He did a lot of good for everyone," Francis said, leading the youth below in a moment of silent prayer for the young man who died.
"We must get used to the good things and the bad things. Life is like this, dear young people," he said, while stressing that "there is something we cannot doubt: the faith of this young man, of our friend, who worked so much for this WYD."
After leading the youth in a round of applause for the example of the young man, he urged them to give thanks to the Lord "because he gives us examples of courage, of courageous youth who help us to go forward in life."
"Don't be afraid, God is great, God is good, and all of us have something good," he said, and bid the youth farewell before telling them to "make chaos" all night in a show of their Christian joy.
Before going to the balcony, Pope Francis connected virtually with Italian youth participating in WYD as part of the July 26-29 youth festival, during which the youth show their culture through performances, singing, and dancing.
During the conversation, Pope Francis took questions from three Italian youth who gave their testimonies and asked a question afterwards.
He spoke to the first young person of the importance of knowing how to keep going in both good and bad moments, explaining that joy helps saves us from being "neurotic."
The Pope then heard the testimony of Andrea, a 15-year-old from the Diocese of Bergamo who was teased growing up. As a result she attempted suicide at the age of 13. However, when she was recovering in the hospital she realized that there was nothing wrong with her, but rather with those who teased her, and that she was stronger than she thought.
While she has moved beyond that period in her life, Andrea said she still feels the pain and finds it hard to let go, and asked the Pope how she can learn to completely forgive the people who teased her.
In his response, the Pope said that cruelty is a common problem among children, and even adults. "Children are cruel many times, and they have that capacity to hurt you where it will do the most damage," he said, noting that cruelty is the "base of all wars."
This cruelty "kills even the good name of another," he said, and warned against the "terrorism of gossip."
"Gossip is terrorism," Francis said, explaining that when a person gossips, "it destroys the dignity, the fame of a person." To gossip, he added, is like "throwing a bomb" that explodes and destroys everything around it.
Pope Francis said this temptation is something that must be overcome with peace and forgiveness, but noted that to forgive "isn't easy, because one can say 'I forgive, but I don't forget.'"
"You always carry with you the hurt of this cruelty," he said, explaining that to completely forgive someone for harm done "is a grace that we have to ask the Lord for. By ourselves we can't, but we have to ask the lord to give us the grace to forgive, to forgive our enemies."
The final question Francis received was from a group of youth and a priest who had been in Munich Feb. 22 when an 18-year-old German teenager of Iranian descent killed nine people and injured nearly 30 others after opening fire at the city's Olympia shopping mall.
After they were forced to cut their trip short and head home, the group still managed to make it to WYD, and asked the Pope how youth can spread peace in a world filled with hate.
In reply, Pope Francis spoke of the difference between peace and hate, explaining that peace always builds bridges, whereas hatred only builds walls.
"We all have a decision to make in life: do I build bridges, or do I build walls?" he said, noting that bridges unite, whereas walls divide.
"In our daily lives the ability to build a bridge when you extend your hand to a friend, you make a bridge. But when you hit, hurt another, you build a wall. Hate always grows with walls," he said, noting that many times when we reach out our hand to build a bridge, we're left hanging.
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He said there are certain "humiliations" like this that we'll have to experience in order to truly walk the path of unity, but stressed that we must "always build bridges."
As the youth gathered to speak to him took up one another's hands in a concrete show of unity, Francis closed by emphasizing that "we must build bridges, not allow ourselves to fall on the ground. No. Always seek the way to build bridges."