The NFL stadium was already rocking when a roar rose from the crowd, swelling above the music and the procession of high-fiving priests leaving the floor.

A Mass of epic proportions had just ended, and the man who celebrated it — 65-year-old Los Angeles Archbishop José H. Gomez — held up his cell phone as he departed the altar inside Indianapolis’ Lucas Oil Stadium. With his other hand on his pastoral staff, Gomez waved his phone’s electronic light to the 22,000-plus teens in the stands. In moments the lights were everywhere.

Taking it all in were 14 teenagers from Sacred Heart Catholic Church, one of two parishes in Hampton Roads to send a delegation to the 2017 National Catholic Youth Conference, a three-day celebration that happens only every other year.

“Most of the kids were like, ‘That’s the most unbelievable thing I’ve ever experienced,’ ” said Kevin Larkin, a Sacred Heart parishioner who accompanied the group, which included his daughter Ashby. “In my mind, if somebody asks you what the Holy Spirit is, that’s it — that feeling.”

The view inside Lucas Oil Stadium during the 2017 National Catholic Youth Conference in Indianapolis.

Sacred Heart has become a regular at the National Catholic Youth Conference under the guidance of its director of Religious Education and Youth Minister, Amy Woods. The nearly two-year process to get the children to NCYC is a parish-wide effort at Sacred Heart, with church members and staff providing critical support through their time, treasure and prayers.

A veteran of eight of the conferences, Woods knows how inspiring and life-altering the speakers, sacraments and fellowship with thousands of Catholic youth can be. After this year’s event, she asked the teens she took to Indianapolis for a few sentences about it.

“I have never seen Catholicism so alive!” wrote Caroline Doyle, 17.

Becca Bonheur, 15, said she can’t wait to go again.

“It was amazing seeing over 25,000 teens gathered in Indianapolis to share and celebrate their faith,” she wrote to Woods.

Larkin, who helped chaperone, said Woods had prodded him for years about the conference, telling him how “it’s just the coolest thing you’re ever going to see,” before he finally agreed to attend with his daughter in 2015.

“That energy and passion — it’s rare, and we’re really fortunate that we have her at Sacred Heart,” Larkin said of Woods.

Woods said she’s such a booster for the conference because of the enduring impressions it leaves. One of the teens she brought to the 2003 NCYC in Houston became a lawyer, and 14 years later she still mentions the trip when they catch up.

A major part of the draw is seeing the larger Church in those 20,000-plus crowds.

The teens “see that they’re not alone, that the faith is alive, that it’s cool to be Catholic,” Woods said.

It’s a chance not only to dance and shout for Christ — Archbishop Gomez’s opening homily drew cheers and included a call-and-response with the kids — but to also participate in powerfully solemn, uniquely Catholic moments. The second night featured Eucharistic adoration inside Lucas Oil Stadium, where the NFL’s Indianapolis Colts play.

“With 25,000 people you can hear a pin drop,” Woods said. “It’s just the most beautiful experience.”

The Sacred Heart teens who attend the conference must participate in and help organize fundraisers, including a casino night, wine festival and silent auction, to help pay for their trip, which costs more than $800 per student. Contributions from the Knights of Columbus, extended family and parishioners also make it possible.

The return on that investment is immeasurable.

This year, after a 2½-hour closing Mass (the adults didn’t hear one complaint about the length), the Sacred Heart contingent joined the throngs of teens heading to their hotels in the cold November night. It was 11 p.m. and they had a wake-up call in less than six hours to get to the airport.

“People are cheering and high-fiving,” Woods said. “They’re just on fire. It’s so hard to explain, but it’s a feeling that you can almost touch.”

The kids were still buzzing on their flight home. The goal, Woods said, is to help them hold onto that energy long after they land.

“Because the world needs their hope, and the world needs their energy to be Christ-like.”