With millions of youth set to arrive in Krakow for World Youth Day in just a few weeks, Cardinal Stanislaw Dziwisz said that "there is no danger" and urged those still on the fence to not miss the opportunity out of fear.

"Come to Krakow, we're waiting for you, don't be afraid!" the cardinal said in a May 30 message to young people around the world. "I say clearly to the youth: do not be afraid."

Cardinal Dziwisz, who served as St. John Paul II's personal secretary for 12 years in Krakow as well as throughout the entirety of his 27-year pontificate, is the current Archbishop of Krakow and is heading the majority of preparations for the July 26-31 World Youth Day (WYD) gathering, which his diocese is hosting.

He spoke to a delegation of journalists and communications experts gathered in Krakow to help prep for the encounter.

The cardinal's plea to the youth of "don't be afraid" is something John Paul II, who instituted WYD, frequently repeated to youth, encouraging them to form a relationship with Jesus Christ and to not allow anything to get in the way.

The WYD event in Krakow, Cardinal Dziwisz said, will be a "celebration of faith, not simply having fun."

He stressed that the theme "is always Jesus Christ, so you must deepen, pray, be together and rejoice in being Christian together with the Pope. In this sense ministry to youth is vital."

Preparations on the ground are moving forward quickly, and everyone is awaiting the millions of youth expected to come to Krakow, he said. Groups from 182 countries have already registered for the event, and the number is expected to rise as the date gets closer.

Recent attacks from Islamic extremists in Europe, such as the November 2015 attacks in Paris and the March 22 attack on a Brussels airport and subway, have aroused fears in some that the large crowd garnered by WYD would be placing a big target on the map for another such incident.

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However, Cardinal Dziwisz stressed that while "the situation in Europe is delicate," Poland itself "is calm. There is no danger, (and) the security services are doing everything to ensure that there will not be any problems."

World Youth Day "will be a fantastic event, we can already feel the atmosphere," he said. While the youth who come do so to meet both their peers and Pope Francis, in Krakow they will also get to know the great Polish Pope, St. John Paul II, much better.

"They want to come to Krakow to get to know John Paul II better," he said, adding that the saint's memory "has remained and the youth want to know it."

Noting how the theme for this year's global gathering, "Blessed are the Merciful," fits seamlessly into Pope Francis' Jubilee of Mercy, the cardinal expressed his hope that the youth who come "will find a personal and communitarian peace, and will bring this message of peace to the world."

"Europe and the world need peace, and through these events we can contribute to changing the atmosphere of the world and of our own countries."

Part of building peace, he said, is being open and choosing not to be fearful in the face of incoming migrants and refugees. He stressed that Poland itself is open to welcoming them, "but with prudence and responsibility."

Responsibility is needed on the part of those who do the welcoming, "because it's not enough to open the doors, we must also ensure life, education (and) work."

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"We are open because in history even the Poles were forced to flee," he said, and noted how many Western countries are "creating walls and barriers" in order keep refugees out. "(But) we in Poland still have not built walls – and we hope we never will."