Huge new Mosque in Rome across the river from the Vatican --->>
NICHOLSON: This experience could be indispensable in coming years as the Catholic Church competes with the rise of Islam. The faithful who worship in this giant mosque in Rome, almost on the doorstep of the Vatican are a powerful reminder of the competition the Catholic Church faces for followers in both the developed and developing world.
JOHN ALLEN: So that mosque in Rome tends to be a tremendous symbol if you like of what sticks in the craw of a lot of Christians thinking about the relationship with Islam.
NICHOLSON: Mario Scialoja is a rare Italian. He converted from Catholicism to Islam, a former Italian Ambassador to the United Nations, hes now the director of Italys World Muslim League.
MARIO SCIALOJA: I dont expect there to be happy to see such a fast growth of the Muslim faith in Italy, but I mean they didnt show any, any resentment for that.
NICHOLSON: Islam is making inroads into traditional Christian areas with a zeal and energy that cannot be ignored. Vatican watcher journalist John Allen has no doubt the Catholic Church is afraid.
JOHN ALLEN: Tremendously afraid. I think the reality is that if you look at the world situation, Islam has about 1.1 billion members, so does Roman Catholicism. Islam is expanding rapidly in a lot of boarder zones where Christianity has traditionally found itself.
NICHOLSON: Arinze is prepared to tackle the contest head on. His approach to interfaith dialogue is straightforward. The aim of the game is more Catholics