Pope Francis celebrated youth during his first Palm Sunday Mass to 250,000 inside St. Peter's Square, initiating Holy Week with a speech on joy, sacrifice and hope.
"Never give way to discouragement; ours is not a joy that comes from having many possessions," he said, stressing the need to resist sadness in the face of hardship. "And please don't let anyone rob you of hope."
The Mass opened with lines of children and the faithful in solemn procession. Following them were cardinals and bishops holding beautifully woven palm fronds. Two choirs marked the rhythm of the celebration as the red-caped pope entered the square, riding in his open-air popemobile.
Francis stopped at the center of the square and stepped onto a platform surrounded by cherry blossoms and olive trees arranged for the occasion. A multitude of hands holding olive branches and palm fronds arose from the stone-paved square, as the pontiff sprinkled holy water over the crowd.
Pilgrims carrying flags from all over the world waved and shouted "Long live the pope!" as he made his way to the white canopied altar on the steps of St. Peter's Basilica.
During Sunday's homily, he became impassioned when he addressed the young people in the crowd. "You have an important part in the celebration of faith," Francis said. "You bring us the joy of faith and you tell us that we must live the faith with a young heart, always, even at the age of 70 or 80," said the pope, who is 76.
Oscar Sobrino, 16, a student from Spain, said Francis was talking to him. "I think this pope is more like one of us, for the simple people, that struggle every day through the economic crisis," said Sobrino, who rode on a bus for 36 hours to see the pope.
Pope Francis promised to go to World Youth Day in Rio de Janeiro in July.
"I will see you in that great city in Brazil," he said. "Prepare well spiritually, above all in your communities, so that our gathering in Rio may be a sign of faith for the whole world."
Since the night of his election March 13, Pope Francis has put humility at the center of his pontificate, expressing his desire for a "Church that is poor and for the poor."
Quoting his predecessor on Sunday, Francis reminded cardinals of their mandate: "You are princes, but of a king that was crucified," he said.
After Mass, Francis climbed into his white popemobile and toured the square for about 30 minutes, leaning to shake hands and high-five children. He also kissed 25 babies.
He also met three disabled people and congratulated a 107-year-old Peruvian man.
"The pope was an inch away from me, when he stopped to kiss a baby," said Clementina Davalos from Buenos Aires. "And I don't even know if I took pictures or what I did, I'm so thrilled!"
Toward the end of his tour, Francis gave his security team yet another jolt as he stepped from the popemobile to greet a family he knew from Argentina. They kissed and hugged before Francis returned to the vehicle and headed for the Vatican walls.
On Holy Thursday, the pope will visit a juvenile detention center in Rome, where he is expected to wash the feet of detainees, re-enacting Jesus' example of humility described in the Gospels. Previous popes did the same with priests in a basilica.
Pope Francis' busy Holy Week schedule will continue Friday with the Way of the Cross procession at the Coliseum, and finally Easter Mass on Sunday in St. Peter's Square.