NEW YORK — With anti-Semitism resurgent in the world, one of the encouraging elements for the Jewish people, particularly if one is to compare things today to the 1930s and 1940s, is the remarkable change in the Catholic Church’s attitudes toward Jews.

In the past four decades, a conceptual revolution has taken place in the church’s relationship with the Jewish people. The first step came with Vatican II and its landmark document Nostra Aetate in 1965, which repudiated the centuries-old “deicide” charge against all Jews, stressed the religious bond shared by Jews and Catholics, reaffirmed the eternal covenant between God and the People of Israel, and dismissed church interest in trying to baptize Jews.

This theological revolution then moved forward dramatically through the papacy of Pope John Paul II. Further documents rejected anti-Semitism and the destructive doctrine of supersessionism — the notion that Christianity supersedes Judaism as the true religion — and the Vatican decided to recognize and establish diplomatic relations with the State of Israel.

As national director of the Anti-Defamation League, I strongly objected to the Vatican upon learning of its reviving the Latin Mass with the conversion prayer.

In short, during the past four decades, the church has made great strides in reversing a 2,000-year history of anti-Semitism.

That is why the decision by the Vatican to restore a wider use of the Latin Mass with the inclusion of the prayer for the conversion of the Jews in the name of taking them out of the darkness is so disturbing. I was in Rome in the days leading up to the announcement of the revival of the Latin Mass containing the conversion prayer, and quickly made my strong objections known in meetings with Vatican officials.

It is not merely that such a conversion call and condescending references conjure up the great suffering and pain imposed on the Jews by the church through the centuries, though that is surely reason enough to be upset. And it is not merely that the tone of this prayer runs counter to the new relationship and language fostered by the Vatican for decades to change Catholic attitudes toward Jews — though that, too, would be reason enough for anger.

The main reason to be disturbed by the return of this Vatican-sanctioned prayer is that it threatens to undermine the conceptual underpinnings of so much that has happened over 40 years — Pope John Paul II’s eloquently expressed statement that Judaism is “the elder brother” of Christianity; that it has a legitimacy and validity of its own; that it has an unbroken covenant with God. It is this conceptual breakthrough — one that has provided the framework for all the specific, positive steps to emerge — that is now being challenged.

What is the right approach to dealing with this concern? It surely should not lead to buying into the notion that this is the same old church, so what do you expect.

Of course, the implementation and filtering down to the pews of the Vatican II changes and subsequent reforms have been uneven and require much hard work and good will. Recent polls of attitudes toward Jews in five European countries and the extreme level of anti-Semitism found in two of them — Poland and Spain — can surely be attributed to the survival of old church prejudices and teachings. We know this to be true of Latin America, as well.

Yet in many places, particularly in the United States, students in Catholic schools are being exposed to positive views about Jews. Most important the Vatican, a hierarchical system, had put in play a conceptual basis for change on the ground wherever the church was present. In the United States, Catholic-Jewish relations are strong — a testament to the variety of interfaith programs involving students, lay teachers, priests and nuns.

So, to be clear, the Vatican is not an enemy of the Jewish people, nor is Pope Benedict XVI.

Rather, the current controversy speaks to the need for direct and honest communication based on the friendly relations that have evolved.

The church must be true to itself and its teachings, and it must understand that reintroducing this prayer — it was removed by Paul VI in 1970 and replaced with a positive one recognizing the Jews’ eternal Covenant with God — will play into the hands of those who are against better relations between Jews and Catholics.

The wider use of the Latin Mass will make it more difficult to implement the doctrines of Vatican II and Pope John Paul II, and could even set in motion retrograde forces within the church on the subject of the Jews, none of which are in the interest of either the church or the Jewish people.

What is important now is for good people within and outside the church to stand up and make these concerns heard. Much is at stake: for the progress already made, for the implementation of Vatican II and the legacy of John Paul II, for the future of Catholic-Jewish relations, and for the rejection of anti-Semitism and recognition of the legitimacy of Judaism.

It is our hope that the decision is not one written in stone and that Catholics and Jews of good will can work together to persuade the Holy See to re-examine its decision.

Abraham H. Foxman is national director of the Anti-Defamation League and author of the book The Deadliest Lies: The Israel Lobby and the Myth of Jewish Control, to be published in September by Palgrave Macmillan.