A 50 year-old declaration of the Second Vatican Council established a new era in Christian-Jewish relations and enabled members of both religions to unite against present-day secularism, Cardinal Timothy Dolan of New York reflected on Wednesday.

Nostra aetate, the council's declaration on the relation of the Church to non-Christian religions, acknowledged what is true and holy in other religions, particularly Judaism, and began a period of dialogue with them.

The declaration "has borne much fruit," remarked Cardinal Dolan May 20, at a conference celebrating the 50th anniversary of the document held at the Catholic University of America in Washington, D.C.

The declaration enabled dialogue between Christian and Jewish leaders, which spurred St. John Paul II to lead a joint response to atheism and secularism.

The shortest of Vatican II's documents, Nostra aetate was widely approved by the Council's fathers (2,221 to 88), though it met with sharp opposition from some Catholic circles for its perceived indifferentism.

Despite this, it marked a turning point in the Church's relationships with other religions, and Jewish leaders are still marveling 50 years later at the positive effects it has produced.

It was "nothing short of a life-saving document," Rabbi Noram Morans, director of interreligious relations for the American Jewish Committee, told the conference in response to Cardinal Dolan's address. Prior to the declaration there existed a centuries-old tension between Catholics and Jews, marked by harrassment and violence of Jews for alleged deicide and scorn for them not recogizing Jesus as the Messiah.

The welcoming tone of Nostra aetate was well received by the Jewish community, as they were now seen as the "elder brothers" to the Christians, remarked Morans.

The document was only the first step toward improving Catholic-Jewish relations, noted both Cardinal Dolan and Morans. Leaders of both religions had to put it into practice and they did exactly that. The U.S. bishops conference played a "singular role" in strengthening the relationship after Vatican II, Morans said.

The relationship has "never been stronger," remarked Cardinal Dolan, adding it "has been remarkably successful" in the United States.

It carries an immense importance with it today as Christians and Jews unite to discuss the most pressing problems for both religions. Chief among these problems is secularism, especially among the youth, Cardinal Dolan insisted.

The "most obvious imperative," he said, is "to reclaim the primacy of God in a world that prefers not to take him seriously, to ignore him, or even to deny him," Cardinal Dolan said. St. John Paul II put this fight against secularism at the core of the Church's post-Vatican II relationship with the Jews because he saw secularism as the chief enemy of the Church, and the Jews among her greatest allies, the cardinal added.

Both devout Jews and Christians acknowledge they world they live in is "simply irreligious," Cardinal Dolan said, quoting Bl. John Henry Newman.

What hasn't helped is the many Christians who ignore talk of sin and redemption, he said, which columnist David Brooks has pointed out in his recent work. Churches preach that everyone is "okay" without acknowledging the need for a savior and redeemer, so attendees begin to look at other ecclesial communities, particularly evangelial megachurches, that preach the need for repentance and salvation.

If people only attended church to make friends, they would have an easier time doing it at a coffee shop or a bowling alley, Cardinal Dolan added.

Both Catholics and Jews can preach the "Biblical reality that popular soothing spiritually would rather have us forget, namely sin and redemption," Cardinal Dolan said.

"They must proclaim 'I am flawed'," he continued. "That is our forte. That's the Jewish and Christian vocabulary. That's what the prophets and the saints proclaimed."

Other problems that both religons face are an abandonment of faith by young members once they become adults or teenagers. Cardinal Dolan related how one rabbi told him that a boy's bar mitzvah would be the last time he would attend synogogue until his son's bar mitzvah. "We Catholics have that, it's called the Sacrament of Confirmation," he recalled jokingly.

The problem is real and serious, he added. "We can hardly ignore their challenge," he said of the youth leaving the religion of their childhood. "It's alarm clock time for both of us."

Another problem that unites the two religions is the international persecution of both Christians and Jews, Morans noted. Christians are the victims of ethnic cleansing by Islamist terrorists in the Middle East and North Africa, and anti-Semitism is making an ugly resurgence in Europe.

These threats demand "mutual admiration and support," he added.

The two religions have found much common ground, particularly through "mutual theological study" and a new candor between leaders over controversies that have arisen since the document. Arguments that previously tore the two faiths apart now strengthen the relations like arguments between members of a family, Cardinal Dolan remarked.

Tensions do exist. Among them, from the Jewish perspective, are the Vatican's official recognition of the state of Palestine, and the role of Venerable Pius XII in the Second World War,  Morans suggested.

However, "we have come a long way in 50 years," he admitted, and there is "too much at stake" for these tensions to divide Christians and Jews.