Cardinal Jean-Louis Tauran, archivist and librarian of the Holy Roman Church, represented the Pope at the museum's inaugural ceremony, which was attended by more than 40 heads of state and government, as well as by U.N. Secretary-General Kofi Annan.
Israeli President Moshe Katsav and Prime Minister Ariel Sharon were also present.
"The building that we have inaugurated is, for the whole world, a warning, a witness and an appeal," said Cardinal Tauran in his Tuesday address delivered in English.
"In acknowledging the immensity of Jewish suffering, we come face to face with the obligation to be vigilant, with the need to reject indifference and with the terrifying void of a world without God," he added.
On behalf of the Pope, Cardinal Tauran said: "When we remember the 'horrible crime committed against the Jewish nation,' that was the Holocaust, we do so because 'these terrible events are for contemporary men and women a summons to responsibility, in order to build our history.'
"The Catholic Church, respecting the uniqueness of Judaism and remaining linked in faith to its heritage, teaches that there is no place or reason for the hatred of Jews. This would be a sin against God and humanity."
Cardinal Tauran quoted words from Psalm 103 with the hope that they would "resonate in this Holy Land, the same words which may have sustained in their torment many of those whom we are mourning today: 'As a father has compassion for his children, so the Lord has compassion for those who fear him. For he knows how we were made ... The steadfast love of the Lord is from everlasting to everlasting."
"If the worst can always come forth from the heart of man, so can the good always equally be made manifest. It is for this reason that we are here today," he said.
The museum, under construction for more than 10 years, houses authentic objects of World War II and of Jewish life in Europe before and during the Holocaust.
Also exhibited are 230 paintings by Jewish artists, many of whom depict their own experiences in the concentration camps.
The museum also remembers the massacres against homosexuals, gypsies and communists, and the eugenic practices carried out by the Nazis against those considered mentally handicapped.
Cardinal Tauran told Vatican Radio today that in viewing these "images, the personal memories, the prisoners' uniforms, the pictures of children torn from their mothers' arms, I would say that one experiences a feeling of oppression and a great question: How is it possible for man to reach that level of barbarism? It is really the mystery of iniquity."
The cardinal revealed that he found "a new atmosphere" in the Holy Land, although the "optimism is restrained, prudent."
"We must always be very prudent when evaluating the future," he said. "What seemed positive to me personally is that there is a will to dialogue, to see one another, to meet, and this is truly very positive."
The cardinal said he was "very moved," as in all his meetings in Jerusalem "everyone asked me to transmit to the Holy Father their best wishes for his health. The rabbis told me that there are prayers for the Pope's health in the synagogues."
"All acknowledge that this Pope as taken gigantic steps in the rapprochement with the Jews," he added. "Thanks also to him, the atmosphere has changed."