Pope, Orthodox Leader Seek to Heal Old Wounds : Christianity: Pontiff speaks of ‘common traditions’ between faiths despite long history of tensions. Patriarch is in Rome to promote reconciliation.

VATICAN CITY — Sharing the altar with the leader of the Eastern Orthodox Church, Pope John Paul II made a passionate appeal this week for unity among the faiths after nearly a millennium apart.

“We cannot remain separate,” the pontiff said during a Mass in St. Peter’s Basilica on Thursday to celebrate the feast day of the apostles St. Peter and St. Paul.

Patriarch Bartholomew I joined the Pope on the flower-ringed altar above the tomb of St. Peter. The Mass was the highlight of the patriarch’s four-day visit to promote reconciliation between the churches.

The Pope, who has made bringing the Roman Catholic and Orthodox churches together a principal goal for the year 2000, offered his most direct appeal for rapprochement.

At the end of the day, the two religious leaders said in a joint statement that unity between their flocks would “increase the influence of the church for peace and justice in zones of ethnic and religious conflict.”

In the former Yugoslav federation, fighting between Roman Catholic Croats and Orthodox Serbs has rekindled old rivalries between the religions.

The churches split in the 11th Century in disputes over the growing power of the papacy. Now, the Pope seeks to use his influence to reunite the faiths.

In their statement, the two leaders also called for both sides to show forgiveness.

The Pope spoke of the “common traditions” between the churches and recounted how Bartholomew took part in the Good Friday procession in Rome last year.

The patriarch stressed a desire to bring the churches closer but noted the need for diversity and serious reflection about the roots of religious discord.

“We must declare to all today’s Christian world our conviction that it is necessary to conduct a self-examination and confession . . . in order for true unity,” he added.

Many of the patriarch’s remarks appeared tailored for his own flock, which is divided over attempts to strengthen ties with the larger and more politically active Roman Catholic Church.

Greek and Russian Orthodox clerics have been particularly critical of overtures to the Vatican, which they perceive as interested in expanding its mark in the former Eastern bloc. There are also serious reservations about allowing the Pope to have any sway over Orthodox followers.

After the Mass, the two religious leaders stood on a balcony over St. Peter’s Square and read a joint creed professing their shared beliefs. Several thousand people remained in the square despite heavy rain from a thunderstorm.

The patriarch, who is called the “first among equals” of the five Eastern church leaders, arrived Tuesday for a series of meetings and events.