Underscoring the close ties between Christianity and Judaism and calling Holocaust denial “madness,” Pope Francis told an interviewer that “inside every Christian is a Jew.”

In a wide-ranging interview published June 13 in Spain’s La Van­guardia newspaper, the pope said dialogue between the two faiths can sometimes be a “hot potato.”

“I believe that interreligious dialogue must investigate the Jewish roots of Christianity and the Christian flowering of Judaism,” Francis said. “I understand it is a challenge, a hot potato, but it is possible to live as brothers.”

Francis’s statement seems to go further than his predecessor, St. John Paul II, who made headlines in 1986 as the first pope to visit Rome’s main synagogue and declared Jews to be the “elder brothers” of the Christian faith.

“Every day, I pray with the Psalms of David. My prayer is Jewish, then I have the Eucharist, which is Christian,” the Argentine pontiff added.

The pope also took the opportunity to criticize Holocaust denial as “madness” while defending the record of Pope Pius XII, who led the Roman Catholic Church during World War II.

Francis will soon have to decide whether to advance the sainthood cause for the controversial wartime pope, who is accused of failing to speak out publicly against the mass murder of Jews. For years, Jewish leaders and Nazi hunters have demanded that the Vatican open up its secret wartime files.

Francis said he was concerned about “everything which has been thrown at poor Pius XII,” while stressing that he sheltered Jews in the convents of Rome and other Italian cities, as well as the pope’s summer residence in Castel Gandolfo.

“I do not mean to say that Pius XII did not make mistakes—I make many mistakes myself—but his role must be read in the context of the time,” Pope Francis said.

Francis added that he breaks out in an “existential rash” when he hears people speak against Pius and the church’s wartime record while ignoring inaction by the Allies fighting against Nazi Germany.

“Did you know that they knew perfectly well the rail network used by the Nazis to take the Jews to the concentration camps? They had photographs,” he said. “But they did not bomb these rail lines. Why? It would be nice if we spoke a little bit about everything.”

During the interview with the Barcelona daily, Francis was also asked about his own security, saying he refused to travel in a bulletproof “sardine can” vehicle because he wants to mingle with ordinary people.

“It is true that anything can happen, but let’s face it, at my age I have nothing to lose,” the 77-year-old pontiff said. —RNS

This article was edited June 23, 2014.