The ambassador led a panel discussion, "Building Bridges of Opportunity: Migration and Diversity" March 8 at the Pontifical North American College; the discussion brought together Vatican officials, experts on migration, other ambassadors, students, priests, religious and people working with immigrants.
Diaz opened the discussion by commenting on the biblical story of Abraham and Sarah welcoming three strangers, who turned out to be God's messengers. The story, he said, "suggests the challenges and opportunities that come with encountering strangers and the ethical responsibility to share life-sustaining resources."
Archbishop Silvano Tomasi, the Vatican observer at U.N. agencies in Geneva and at the International Organization for Migration, told the conference, "The church sees migration as a resource for development, a positive phenomenon.
"In the long experience of the church, migrants are a contribution (to society); they bring something positive, constructive, even though they take the dirty and difficult and dangerous jobs in society, they bring themselves, their tradition, their identity" to a new land.
Archbishop Tomasi also said that throughout history, migrants brought Christianity to new lands. Even today, he said, Catholics from the Philippines, India and Sri Lanka are founding parishes in the Gulf States where they have migrated for work.
In North America and Europe, he said, "the missions are now coming to us." While Catholic missionaries used to set off for Africa or Asia, now Africans and Asians are immigrating, giving every North American and European Catholic a chance to witness to the Gospel through a warm welcome, concrete assistance and introductions to the Gospel message.
"The first right of people is the right not to be forced to migrate," he said, but given civil unrest, climate change and the global economy -- and not just during the current crisis -- people do and will continue to feel they have no choice but to seek safety and a better life abroad.
"These people aren't tourists," he said. At the root of migration, there is the relationship between poor countries and rich countries. "As long as the disproportionate gap exists between rich countries and poor countries, we will have continuing migration."
The archbishop said that while migration always benefits a host country in the long term, the difficulties of welcoming and integrating newcomers with different languages, cultures, habits, religions and lifestyles are immediate and local, which makes placing heavy restrictions on migration a popular position for politicians running for office every four or six years.
Cardinal Gianfranco Ravasi, president of the Pontifical Council for Culture, said education -- both in schools and in religious education classes -- is a key to helping people recognize the human dignity of migrants and the cultural richness they can bring.
In many parts of Europe, he said, there is a fear of the growing number of Muslim immigrants and a sense that somehow Europe is being challenged to give up some of its Christian traditions and culture to make space for them.
As Christians and Muslims meet in neighborhoods across Europe, he said, there will be no real dialogue, no dynamic sense of cultural diversity unless Christians start taking their own faith seriously.
In several Italian towns, politicians have been fighting court cases brought by Muslims or atheists to remove crucifixes from school rooms and other public buildings. But, Cardinal Ravasi said, many of those towns "are pagan," because the townspeople "defend the idea of their faith, but don't practice it."
In too many parts of Europe, he said, Christianity is part of the local folklore and dictates the town feast, but has nothing to do with the daily life of its residents.
"Europe is in difficulty with Islam because it has lost its identity, its Christian face," he said, and without a sense of identity on both sides, dialogue is impossible.