KRAKOW — “God, where are you?”

When the crowd applauded Tuesday night after Cenacolo’s performance of Credo, outside of the Tauron Arena, they weren’t just giving thanks for a well-done play but celebrating light and mercy, love and freedom.

Freedom was the theme of the day in the WYD Mercy Center. And Cenacolo, a community of faith for men and women who “have been to hell and back” as one priest who is close to them put it, is the personification of the message and the miracle of mercy.

Cenacolo was founded by Mother Elvira Petrozzi in 1983 in Italy for young men and women caught in the darkness of despair and especially of addiction. Many of us might not even be alive today, never mind here, if it weren’t for her and the community she established, as Polish-born Paul Szopa emphasized as he stepped out of the sound booth while Christ’s Crucifixion was promising the hope of the Resurrection on stage.

Applauding at the end of Credo is a celebration of the resurrection that happens at the healing power of Christ in the sacraments. Each of the men and women on stage have experienced it in their bodies and souls.

I don’t typically cry in arenas. But at the WYD Mercy Center sponsored by the Knights of Columbus here Tuesday night, I did. And I was far from alone.

The Knights of Columbus are hosting the arena for the week for English-speaking pilgrims for Mass, adoration, and other programming.

It was long past the point where the Holy Spirit had taken over the place when the popular Christian artist Matt Maher led 20,000 young people in inviting Him in song.

The Mercy Center is the largest venue in Krakow, a city where not all that long ago it was illegal to pray in public. And yet, in this city of Saint John Paul II, our contemporary exemplar of heroic virtue, the young people (and adults accompanying them) believe prayer is the solution to just about every problem you can think of seems present.

In a meditation during a Eucharistic procession and Benediction around and through the arena, Bishop Robert Barron talked about the cross of Jesus Christ, and how it unleashes the power of Divine Mercy.

There was “nothing more terrifying” than death on a cross, he said. And yet, he said — pointing to some of the saints of this city, like St. Maximilian Kolbe who died at Auschwitz when he took the place of a married man, whose images are throughout the Tauron Arena this week  — “look at the power they unleashed.”

If you visit the Sanctuary of John Paul not too far from here, a side chapel is home to his bloodstained cassock. It seems to radiate “courage.” And “trust.”

And it points to the Blessed Mother to whom he attributes the fact that he did not die that day.

St. Mary is the basilica in the main square here and I’m not sure you’ve been here if you don’t feel closer to her, whose life and queenship in Heaven is about bringing us closer to God.

Tuesday night was a “mercy night” in the Mercy Center. Mercy is overflowing in this place, in this Jubilee Year of Mercy, in almost everything Pope Francis says and does. About 20,000 young people – and it would have been more: there were 2-5,000 who had to be turned away because it hit capacity – encountered the presence of Jesus, with love and honor and praise overflowing.

The night began with Maher and Audrey Assad singing about the peace of Christ that is “so unexplainable.”

You call me deeper still into love, love, love.

By the end the crowd was singing:

Here I am Lord. Is it I, Lord? I have heard you calling in the night. I will go Lord, if you lead me.

“The energy” in the arena is what was most commented on to me during the course of the day. And it only increased, culminating in hearts open to the Real Presence in gratitude and praise and hope and trust in the glorious victory already won.

This is my first World Youth Day. I almost went to more than one of them – I even had a hotel room for Rio last time around. But I figured watching from afar you got the best of it.

Not true. The best of it is in the encounter with these young people, encountering one another and Jesus Christ Himself in the Eucharist and His Body, the Church.

“We are not the Church of tomorrow. We are the Church of today,” is how Maher ended the night.

When one man invited me to join the 20,000 last night in adoration (he saw me going to get a photo to tweet out for Twitter) he had exactly the right idea.

Do what Pope Francis models: Pour yourself into prayer and be invitational.

It’s in authentic Christian witness and the going forth and sharing — to all the nations, as the Gospel says — that all the darkness we know exists back home and throughout the world might meet light, in the joy of real, Passionate, challenging, transformative faith that radiates from this Mercy Center in these days.