As huge crowds of youth flock to Rio de Janeiro for World Youth Day 2013, some participants from past years are currently living out vocations discovered at the global youth events.

Sr. Kathryn Maney of the Marian Sisters of Lincoln, Neb., says that at the 1993 World Youth Day in Denver, she saw the joy and peace of religious sisters and that it "drew my heart."

Begun in 1986 by Blessed John Paul II, World Youth Day takes place every two or three years. Several million young people from across the globe are expected to attend the event in Rio de Janeiro, Brazil, this year on July 23-28.

One of the events to take place at this year's gathering is a four-day vocations fair, which will feature around 150 different religious organizations.

In the past, World Youth Day events have been credited with sparking vocations, with many young people saying that their eyes were opened to God's call for their lives.

"That love of Holy Mother Church that was instilled and inspired within me by God's grace at World Youth Day in Denver was definitely a stepping point in the direction of the Lord leading me closer to himself in the religious life," Sr. Kathryn told CNA on July 12.

A sophomore in high school when she attended the event, she said that it led to her "falling in love with the Church."

"Just seeing the universality of the Church and the spiritual fatherhood of Blessed John Paul II and the witness of the faith of the other young people with me was a great inspiration and a grace."

Being able to attend World Youth Day again in 1997 in Paris, just before entering the community of the Marian sisters, was "a tremendous help in solidifying that sense of being called to be a spouse of Christ," Sr. Kathryn said.

Fr. Scott Courtney, a priest of the diocese of Lincoln, was also inspired in his vocation by a pilgrimage to World Youth Day. A young seminarian at the time, it was the theme of Denver's youth gathering that gave Fr. Courtney "the verse which I try to live by."

That verse was John 10:10, "The thief comes only to steal, slaughter and destroy, but I came that they might have life, and have it more abundantly."

"That World Youth Day was the first that really inspired me to live that abundant life more," Fr. Courtney said.

"Seeing the Holy Father vibrant and joy-filled was a great experience," he recalled. "I think for the first time I experienced in Denver that mark of the Church which is 'catholic.'"

Also nurtured at World Youth Day were the vocations of Joe and Karissa O'Hearn. Now married, the couple met on a pilgrimage to Cologne, Germany, in 2006. 

The summer before their senior year of high school, the O'Hearns met at the airport on the way to Germany, their friendship developing over the period of the trip.

"From World Youth Day this huge conversion had sparked in him," Karissa told CNA about her husband, who had been complacent in his faith before the pilgrimage.

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She noted that "what I had with Christ didn't conflict with what I had with Joe. The two never impaled each other…there was nothing I wanted to keep from Christ about our relationship."

Reflecting on one night of the pilgrimage in particular, when they both spent time in adoration together, O'Hearn said that "there was just this warmth and this peace that came over me…I could totally focus on Christ. It was the first time I wasn't making this happen, but God was laying this gift before me."

Now married for four years and expecting their second child, O'Hearn observed, "Looking back and thinking about what Christ has shown me, there are many things, many gifts that have come through our marriage."

"I've always been this really dorky, middle-school type romantic," she explained. Thinking back on meeting her husband at World Youth Day, she said that "Christ really showed me – all those romantic desires, all of the things you created from sitcoms – those desires I've placed in your heart."

Christ says, "I took you all the way to Germany just to meet your spouse and know and encounter me," she said.