“That’s really cool,” a bat mitzvah girl said to me last Shabbat, as we were about to leave my study to ascend the bima. She was referring to a photograph of me with President Obama. The photograph that stands beside it, of me with President George W. Bush? “Not cool!” she declared emphatically.

“I’m going to Rome in two weeks for an audience with Pope Francis,” I told her. “Extremely cool!” she exclaimed. “Do you know the story of the rabbi and the Pope?” “Tell me,” I said. She replied, “The Chief Rabbi of Rome was invited to meet the Pope. It was the first time in history. When they met, the rabbi said, ‘Your Holiness, I am honored to present you with this letter. It has been passed down for thousands of years in the hope that this occasion would someday occur.’ The Pope took the letter and opened it. It contained the bill for the Last Supper.”

Growing up in freedom and safety, my sweet young student could not know how much pain lies beneath the sunny surface of that joke. For most of the past two millennia, relations between the Church and Jews were indescribably awful. Reviled as alleged “Christ-killers,” declared by the Church Fathers to be cursed by God, objects of contempt, deemed unworthy of salvation, preserved only to bear witness to the consequences of rejecting Jesus as Christ, subjected to discrimination, oppression, forced conversion, inquisition, even violence, countless generations of Jews understandably feared and detested the Church. Most tragically of all, the Holocaust could not have occurred without centuries of Jew-hatred stoked by the Catholic Church.

Catholic-Jewish relations have undergone a profound transformation since the Second Vatican Council, convoked by Pope John XXIII in 1962, and its unprecedented declaration, Nostra Aetate, which stated that “…the death of Christ…cannot be charged against all the Jews, without distinction, then alive, nor against the Jews of today.The Jews should not be presented as rejected or accursed by God, as if this followed from the Holy Scriptures…[T]he Church, mindful of the patrimony it shares with the Jews and moved not by political reasons but by the Gospel’s spiritual love, decries hatred, persecutions, displays of anti-Semitism, directed against Jews at any time and by anyone.”

Steadily, but not without occasional difficulties, relations between the Catholic Church and world Jewry have progressed for half a century. A joke that once must have resonated with pain, suffering, anger and bitterness is now tame, reduced to being merely cute and modestly amusing. If anything, I and the other Jewish leaders invited to the papal audience will present gifts and goodwill, not bills. We know that we will be meeting a friend, not an adversary and certainly not an enemy.

We know this from the relationship Pope Francis enjoyed with rabbis and the Jewish community in Argentina, and from the obviously genuine kindness, humility and sincerity with which he resonates. And we know it from the letter he wrote to the chief rabbi of Rome the day of his election to the papacy, in which he said, “I eagerly hope to be able to contribute to the progress that relations between Jews and Catholics have experienced since the Second Vatican Council, in a spirit of renewed collaboration, and in service of a world that might be more and more in harmony with the Creator’s will.”

Catholic-Jewish relations, though greatly improved, are certainly not perfect. Tensions and challenges remain, and just as there have been numerous setbacks during the past 50 years, others will surely occur, but the trajectory of progress will continue. The Church may not have paid in full the debt it owes the Jewish People. Indeed, doing so may be impossible. But it has made a substantial downpayment.