Pope Benedict XVI told the faithful gathered in Saint Peter's Square on Sunday that "nothing can keep us from this onerous and fascinating duty" of spreading the Christian faith throughout the world.

The pope referred to guidelines issued earlier this month by the Vatican's doctrinal office on the missionary policy of the Roman Catholic Church.

"The document serves as a reminder to all Christians, in a situation in which it is often not clear to many faithful themselves the reason for evangelizing, that accepting the Gospel pushes one to communicate the gift of salvation," the pope said during the traditional Sunday noon Angelus prayer on the last Advent Sunday before Christmas.

"Nothing can exempt or keep us from this onerous and fascinating duty."

The pope also anticipated "the joy of Christmas," saying that it fills believers with a hope that "pushes us to announce the presence of God."