"Señor, aquí estoy ... Here I am," Jennifer Aguilera sang, transitioning to a famous Catholic song, smiling widely as youth from all corners of the United States came to one of Lisbon's parks for an Aug. 2 National Gathering at World Youth Day.

"Living for your word, I want to say 'yes,' as Mary did, Lord," Aguilera, who is in Lisbon with a group from California, sang, telling OSV News later: "I have consecrated myself to Mary. To me, listening to her and saying my 'yes' to her and to Christ is amazing."

Over 1,300 groups comprised of more than 28,600 individuals from across the United States joined the Portuguese WYD. The U.S. is among the five largest delegations participating in WYD, which is taking place Aug. 1-6 in Lisbon.

On the evening of Aug. 2, they gathered in Quintas das Conchas e dos Lilases Park along with U.S. bishops that greeted them, lining up on the stage and introducing their dioceses. Sixty bishops came to Lisbon from the U.S., and more than 35 serve as lead bishops for the daily catechetical sessions called "Rise Up!"

"World Youth Day is without a doubt a gift, a gift from God inspired by the Holy Spirit through St. John Paul II, and it has been a gift that just continues to give to the church," Bishop Edward J. Burns of Dallas told OSV News. "One of the things I learned when I was working at the United States Conference of Catholic Bishops is that of all the men who are ordained every year to the priesthood, 35%-38% of them went to World Youth Day. This is such an inspirational moment," he added.

Tony Meléndez, a Nicaraguan-American guitar singer and songwriter who was born without arms and learned to play the guitar with his feet, cheered the youth ahead of the event.

"We come here to energize people. We come here to pray with people. We come here to just be with them in prayer and song. So I'm excited to be here for another World Youth Day," he told OSV News.

Meléndez's life changed on Sept. 15, 1987, when he sang "Never Be the Same," while playing the guitar with his feet in a special performance for John Paul II. The pope, visibly moved, descended from his chair and embraced Meléndez, encouraging the singer to continue "giving this hope to all, all the people."

"The young people are alive. They want to be part of the church. They come in millions, and we just got to give them that opportunity. Do they stray? Sometimes, yes. But we got to keep feeding them spiritually," Meléndez said.

That's precisely what Silvia Torres, a pilgrim from the Archdiocese of Galveston-Houston, experienced in Portugal.

"World Youth Day in Lisbon is beautiful. It is welcoming. You feel God's presence in every place that you go to, every corner that you turn into, every person that you say hello to, they just greet you and you see Jesus with every person that you meet," she told OSV News.

Her first WYD was in Krakow in 2016, and now in Lisbon, she is feeling most touched by the visit to the sanctuary of Our Lady of Fátima, where she managed to do a pilgrimage on her knees.

"I was able to do it from the beginning up until her chapel. And I did dedicate that for my mom and for her health. And it was a beautiful experience," she said.

"I gave (Mary) all of my worries, all my stress, all my insecurities about the future. And I leave with peace, knowing that she is always looking out for us, that she is always with us. I am blessed enough to have my mom here on earth and my mom in heaven," Torres said.

U.S. Ambassador to Portugal Randi Charno Levine greeted young people at the beginning of the event, with the youth cheering loudly when she said she met Pope Francis earlier during the official welcome. The pope arrived in Lisbon Aug. 2.

Bishop Robert Barron of Winona-Rochester, Minnesota, gave a keynote address to American youth.

"Let Christ come to life in you, set your heart on fire and then you'll know who you are," he said. "Through your mission, you will find joy and transfigure the world."

"The Gospel says when you hear about the Lord Jesus Christ, and he takes possession of your heart, you know who you are," Bishop Barron said.

Bishop Burns led the Eucharistic procession at the end of the event. Amid the National Eucharistic Revival taking place in the U.S. and ahead of the upcoming National Eucharistic Congress, bishops are encouraging youth in Lisbon to turn to Christ and to bring their problems and questions to him, especially in Eucharistic adoration.

"What I see are these young people (that) are searching for Jesus Christ. I mean, they want to find him, and they've traveled the world to come to World Youth Day, finding him in the presence of the Holy Roman Catholic Church to celebrate in the person of Pope Francis, the successor of Peter, the one to whom Jesus said, 'Peter, you are rock. And on this rock, I will build my church and the jaws of death shall not prevail against it.' So you look at this church, and it is alive," Bishop Burns said.

In a challenging world, he added, youth need courage and "some of the challenges they have are how to be courageous in proclaiming the truth in the world," he said, adding that the challenge is also how to "work very closely even with their peers in bringing them to the truth and to the church and to our Lord Jesus Christ."

Edgar Mondragón, a young teacher from the Archdiocese of Galveston-Houston, said that what he would like to bring home from WYD in Lisbon "is to be able to just pour out what I receive here onto the people I work with, my friends, my family, my students."

"It's in giving that you receive. So just be able to give them the love, show them the light of Christ," he said.

Bishop Burns said he hopes young Americans "will bring home an urgency to proclaim the Gospel message," referring to the WYD theme "Mary arose and went in haste."

"There is some urgency in our spiritual lives that I hope that they are attentive to," he said.

Torres shares the feeling and wants to "be a young adult that's energetic and that goes out to the streets and wears Converse and drinks Coca Cola and don't be afraid to be authentic."

Meléndez told OSV News: "I know some will go home, and it might not mean that much to them, but they had a hard time," referring to the hardships of a pilgrimage, which is what WYD primarily is.

"But some will remember this forever. And they take it in their heart and they'll say: 'You should have been there to see millions of Catholics coming from around the world there in Portugal in 2023.' So it's powerful. It changes lives. What changes lives? Jesus," he said.