Sitting side by side, Pope John Paul II and the spiritual leader of Orthodox Christians made passionate appeals yesterday for unity between their churches, while acknowledging serious obstacles remain.
With Ecumenical Patriarch Bartholomew I of Constantinople saying the joy of the occasion was clouded by "disappointment" over lack of unity, the pope assured him that Roman Catholics are irrevocably committed to mending the rupture between the Eastern and Western branches of Christianity.
These efforts "cannot be abandoned," said the pope, urging all Christians to intensify them.
"The road is certainly not easy or without obstacles," the 84-year-old John Paul declared, holding up well in the two-hour service despite his frail condition.
Both men insisted their presence on the steps of St. Peter's Basilica was not merely ceremonial but a genuine attempt to mend their split in the 11th century over the growing power of the papacy, with more recent tensions over the expansion of the Catholic Church's reach in the former Soviet Union.
Bartholomew, speaking in Italian like the pope, acknowledged it could still take some time to achieve the goal but said there is a "sincere desire to remove obstacles."
The patriarch, a gold and purple cape over his black robes, sat to the right of John Paul, who wore red vestments, at the flower-filled altar for a Mass on the feast day of St. Peter and St. Paul.
Vatican officials said the two men will sign a joint declaration later in the week. A top cardinal, Walter Kasper, suggested the churches might agree to resume theological talks interrupted three years ago and establish regular contacts.
At a meeting earlier in the day, the pope again expressed remorse over "painful episodes of history" that have darkened their relations.
"In particular, we cannot forget what happened in the month of April 1204," the pope said, referring to the sacking of Constantinople by Crusaders that contributed to the collapse of the Byzantine Empire about three centuries later.
"How can we not share, at a distance of eight centuries, the anger and the pain?" the pope said.