OŚWIĘCIM, Poland — At the infamous German Nazi concentration and extermination camp of Auschwitz, among the first things one encounters upon entering is a quotation from the Spanish thinker George Santayana: “Those who do not remember the past are condemned to repeat it.”

It’s almost impossible not to hear those words echo in this place, where Pope Francis will visit in late July while in Poland for the Catholic Church’s World Youth Day festival.

Upon arrival at Auschwitz under the Nazi regime, pregnant women, children, the elderly, and the infirm were declared unfit to work, and hence to survive, by a Nazi doctor, meaning they were “thrown away” into gas chambers. The vast majority of the rest didn’t survive more than a year as a result of mistreatment, hunger, coldness, desolation, untreated illnesses and slave labor.

Even today, their suffering is palpable in the markings left by the bare hands of people desperate to escape death.  By the end, it usually couldn’t come fast enough.

Twin children were submitted to experiments so unimaginable that guides who explain some of the most sordid details of the “life” of the prisoners refuse to voice them, even dodging the question when asked directly.

More than 1 million Jews from all over Europe, 150,000 Poles, 25,000 Gypsies, 15,000 Soviets and 25,000 prisoners from other ethnic groups were deported to Auschwitz by the Germans, who killed 1.1 million of them.  90 percent of those killed were Jews.

The suffering was such, that when he visited in 2006 Pope Benedict XVI dared to question God amid what he described as a “stupefied” silence: “Where was God in those days? Why was he silent? How could he permit this endless slaughter, this triumph of evil?”

“I pray to God not to allow a similar thing ever to happen again,” he said.

Benedict also acknowledged that as a “a son of the German people” he could “not fail to come here. I had to come.”

St. John Paul II, a son of Poland, who grew up in the nearby city of Wadowice, voiced similar words when he visited it for the first time as pope in 1979, though he had been in Auschwitz several times before.

“It was impossible for me not to come here as pope.” John Paul said.

Francis will follow the steps of his predecessors this July, when he travels to the nearby city of Krakow to join hundreds of thousands of young people from over 180 countries gathered for World Youth Day.

According to Father Antonio Spadaro, who edits a Jesuit-run journal in Rome and is a confidante of Francis, the current pope, like John Paul II and Benedict XVI before him, “finds this to be a mandatory, one could say fundamental, stop.”

As with Benedict, during his visit Francis will share an interreligious prayer with leaders of the local Jewish community.

Spadaro believes that just as the German pontiff questioned God during his visit to Auschwitz, Francis is bound to question humanity, as he did in 2014, when he visited the Holocaust Memorial Yad Vashem, in Israel.

“Adam, where are you?” Francis asked at the time. “Adam, who are you? I no longer recognize you. Who are you, o man? What have you become? Of what horror have you been capable? What made you fall to such depths?”

“In Auschwitz he will ask this question again to remind men and women that what was done here is incomprehensible,” Spadaro told Crux minutes after a visit to the extermination camp.

On the other hand, the priest added, “in the relationship with God, Auschwitz is the icon of a world that doesn’t know mercy.”

Spadaro, who’s been close to the Argentine pontiff since the beginning of his pontificate, gave two more reasons as to why Francis’ visit to Auschwitz is so important.

One is the fact that doing so during World Youth Day will give him the possibility to shine the light of mercy over young people from around the world, so that they in time can bring it back to their own countries.

That, in turn, is tied to the third reason cited by Spadaro: showing the importance of God’s mercy and his love to a world where divisions, violence, and extreme nationalisms seem to be flourishing.

“Around the globe, political figures are emerging because they promise to build walls,” Spadaro said, comparing the barbed wire fences that are being built throughout Europe to keep immigrants out to those same fences which abound in Auschwitz.

“The jubilee of mercy represents the response to this drama: A world without mercy, without God, that is Auschwitz,” he said.

According to Father Manfred Deselaers, a German who’s been working in a Centre for Dialogue and Prayer in Oświęcim [Auschwitz is Oświęcim in German] for the past 20 years, this “death machine” is not only a place where one is shocked by the memory of evil – though that, he said, definitely happens here.

“It’s also a place where you come for reconciliation,” he said. “It can be a positive place, for dialogue and encounter,” two key concepts in Francis’ pontificate.

Having encountered hundreds of survivors, both Jewish and Polish, as a Catholic priest and a German, Deselaers said he’s learned that these people “don’t want for us to use this as a reason to become depressed.”

“On the contrary,” he said, “they want for us to learn from it, to learn to respect one another, create friendships that would help build a better world.”

“This is a school for young people, here they learn to value each other, and it creates the awareness in them that we have the responsibility to learn to live with one another,” Deselaers said.

Deselaers too believes that Francis’ visit to Auschwitz with the world’s Catholic youth awaiting his message, could have a positive, long-term impact.

He warns that just like almost 80 years ago, when no one thought something like this could happen, “we now know that because it did, it remains a human possibility.”

“We trust the word of Christ has the last word, also about Auschwitz,” Deselaers said. “And we hope the memory of this horror doesn’t destroy trust in God and humanity, but calls us to love more, and trust more, and to heal the wounds.”

The hope that the almost two million people who visit this place are conscious about the dangers of history repeating itself is what moves Agata Andrzejewski, day after day, to tell the history of what happened to the museum’s visitors.

“It’s important to know about these people, to remember their stories, so that this doesn’t happen again. I hope we’ve learned, and that we remember, so we don’t repeat it,” she told Crux.