KRAKOW, Poland — Facing a uncertain time in Europe, with terrorist threats, a massive refugee crisis and a war in Ukraine, Cardinal Stanislaw Dziwisz of Krakow understands why some young people, and perhaps their parents, may be leery about travel to Poland in July for the Catholic Church’s World Youth Day.

In the teeth of that apprehension, Dziwisz has a simple message, borrowed from his mentor, St. John Paul II: “Be not afraid!”

“The situation in Europe is delicate, but Poland is a safe country, and will be so during the event,” Dziwisz told a group of international journalists on Thursday.

“The security forces are doing everything needed to guarantee it is so,” he said.

Safety concerns for the millions of pilgrims expected to participate in the July 26-31 event have mounted in recent weeks, going beyond the usual anxieties for any big gathering: A confidential report claiming that one of the planned sites poses “high risk for the life and health of people” was leaked to the press.

That report, from Poland’s Government Center for Security, reportedly says the site lacks proper access and evacuation routes, a major power line runs nearby, and a leak in the nearby dikes on the Vistula River also could pose a threat.

In addition, summer rain could turn the site into a swamp, and according to the report leaked in early April, sufficient medical support has not been planned.

Dorota Abdemoula, spokeswoman for World Youth Day, addressed those concerns on Thursday by saying the information on the report is inconclusive, and that the organization is working to address all the issues raised.

She said that in effect, the document presented a “to do list,” not a set of reasons why the place wouldn’t work.

Furthermore, she said, all the security forces involved, including the Vatican’s, agree that the place chosen for the two closing activities, meaning a prayer vigil and a Mass, is the best location available.

Two million people, between pilgrims and Krakow’s own citizens, are expected to be in what is being called the “Mercy Field” for those events, which will be led by Pope Francis.

For Dziwisz, who for over three decades worked closely with the Polish pope as his personal secretary, the “Do not be afraid” has a double meaning.

St. John Paul II used this phrase on the first Mass of his pontificate, saying “do not be afraid to welcome Christ.”

“This is a celebration of faith,” Dziwisz said. It’s not a ‘come and have fun’ event but an expression of the desire the youth has to encounter Christ, the Gospel, Pope Francis and each other.”

In today’s world, Dziwisz said, when the young are seemingly uninterested in God and the faith, “you need a special charisma to talk to the youth,” and this, he added, is a quality shared by John Paul II and Francis.

“Those who have it, can draw the youth to the faith, and they want to come: John Paul understood that they want a leader, they want a shepherd willing to address their concerns,” he said.

“St. John Paul II really loved young people, and he always spoke the truth to them. He was demanding, as he expected a lot [from them], but he did so with love,” Dziwisz said.

Referring to young people in Poland and around the world who may feel a stronger connection to the late pontiff than Francis, Dziwisz said, “During World Youth Day, that same rapport will be born, because Francis has this charisma too.”

According to the cardinal, this is not the only thing the two popes have in common.

Asked about the heritage of John Paul II for this event, Dziwisz didn’t hesitate: Mercy.

The Polish pope was a strong promoter of the Divine Mercy devotion, introduced by a Polish nun named St. Faustina Kowalska in the early 20th century in response to a series of mystical experiences.

“John Paul was an apostle of mercy, together with Faustina, and so is Francis,” he said.

Mercy has been a common thread in the current pontificate, so much so that Francis called for a Jubilee Year of Mercy for 2016, and has even authored a book, “The name of God is Mercy.”

The Shrine of the Divine Mercy, and the adjacent convent where Faustina died are in Krakow, and Francis will visit both during his stay in Poland.

Mercy, Dziwisz said, is the only thing that can bring peace to the world, and the July gathering will attempt to bring peace to the youth, so that they in time can go back to their countries of origin and spread it around the world.

“We want for World Youth Day to help build peace in the world, and especially in Europe, where countries are so divided,” he said.

Talking about the divisions of the continent, the prelate also spoke about Europe’s migrant crisis.

Following the March terrorist attacks in Brussels, Polish Prime Minister Beata Szydło announced that the country would not be taking any more refugees, which was received with ire by other European nations.

Dziwisz said it’s important to remember that this 40-million strong country already hosts a million people who came over from Ukraine in recent years looking for better opportunities. In addition, Poland is currently struggling with 1.5 million unemployed people.

Over 2 million Poles currently are living in Germany and the UK, he said, because they themselves wanted a brighter future.

For this reason, Dziwisz said, “We’re open to receive these refugees, but keeping two concepts in mind: prudence and responsibility.”

He also said that Poland has the responsibility of welcoming those fleeing their home countries to save their lives because, throughout history, the Polish people had to themselves leave for other European nations or America, fleeing from danger.

“Whoever wants to save their lives is welcomed,” Dziwsz added.

Young people from at least 182 countries, including Iraq, Syria and Saudi Arabia, will start arriving in Krakow on July 25. Francis is to join them two days later and participate in prayers, a procession and a night vigil.

An estimated 550,000 people have registered so far to participate in this pilgrimage, including 12,000 priests and close to 1,000 bishops.

Francis will also visit the Jasna Gora sanctuary in Czestochowa and the memorial of the Auschwitz Nazi death camp, where he’ll share a prayer with local Jewish leaders.