Pope Francis in Poland on Thursday during the occasion of the World Youth Day festival called on young people to strive for a better world, telling them not to "throw in the towel."
"It hurts me when I meet young people who seem to have retired before their time," the pontiff said at a welcoming ceremony before hundreds of thousands of young worshippers in the city of Krakow.
"It worries me, when I see young people who have thrown in the towel before they stepped up to fight." Encouraging action for change, Francis said "it is beautiful and it comforts my heart to see you so rebellious," adding that the church could learn from such things.
The meeting in Krakow rounded off the second day of his trip to Poland, which coincides with this year's World Youth Day festival.
Earlier in the day, Francis headed to Czestochowa, Poland, to pray before the country's most important Catholic icon: the Black Madonna.
The private viewing of the icon was followed by a special Mass to commemorate 1,050 years since Poland was Christianized.
That open air mass led to a fright as the 79-year-old pope - censer in hand - stumbled but was righted again with the help of two assistants and continued the Mass as planned.
The pope's trip to Poland is poignant, since officials here are struggling to show themselves as welcoming to the world even as they tussle with the rest of the European Union about concerns that the current government is trying to enforce a rigid conservatism out of step with the rest of Europe.
Francis, who has made a point of trying to modernize the church, has also clashed with Poland, telling its leaders Wednesday that they should share the burden of accepting the crush of refugees who have arrived in Europe since last year. Poland has fought hard against calls to take in more of the asylum seekers.
Nevertheless, after meeting with the pope, Polish Catholic officials assured the country that Francis had not come to lecture, but to celebrate World Youth Day, which is expected to draw more than half a million pilgrims to Poland before it ends on Sunday.
The pope is expected to stay through the end of the event. On Friday, the focus will be his visit to Auschwitz, the death camp set up in Poland by occupying Nazi forces during World War II.