The debate, organized April 8 in Milan, attracted Cardinal Walter Kasper, president of the Pontifical Council for Promoting Christian Unity, and Lutheran bishop and theologian Margot Kässmann.
In his address, reported by the newspaper Avvenire, Cardinal Kasper explained that pluralism "is a fundamental challenge to Christianity today."
The challenge emerges amid talk of the danger of a "clash of civilizations," he said. Such a challenge, must be addressed by going all the way with dialogue, especially between religions, he added.
Asked if there is a danger that all religions will be seen as being on the same level, the cardinal responded: "We must adopt the stance indicated by the conciliar statement ´Nostra Aetate,´ which does not reject anything found in other religions that is true and holy."
Cardinal Kasper clarified that "the salvation brought once and for all by Christ is manifested in these seeds of truth."
Thus a Christian has the mission to proclaim this salvation, "placing a God at the center who has manifested himself as absolute love," he continued.
"This truth does not crush the other; it knows how to make room for it to the degree that it shows aspects of a mystery that no human concept can exhaust," Cardinal Kasper added.
Margot Kässmann agreed with the cardinal in his description of pluralism as a great danger for, but not only for, Christianity.
"If Europe loses its soul, it runs the risk of reneging on those values that Christians have succeeded in affirming, even, perhaps, at the price of difficulties between them," the Lutheran theologian emphasized. "We are in agreement in saying that the European Charter has unjustly neglected this aspect."
Cardinal Kasper added: "No good service is done to other religions if we allow ourselves to be fascinated by others´ positions: I have seen Christians who knew everything about the suras of the Koran, but had not opened the Bible in years. This is not the way to walk together."