Vatican City - Pope Benedict XVI pressed ahead with his appeals for a unified church Thursday as he a celebrated a Mass in St. Peter's Basilica attended by a delegation of Orthodox Christians.
"We again implore, on this occasion, that such a a gift be granted soon," Benedict said.
Benedict has made uniting all Christians and healing the 1,000-year-old rift with the Orthodox a primal goal of his papacy, although he acknowledged key differences.
He combined his call for Christian unity with a warning that the Catholic Church was threatened by those seeking to "push it outside the world."
"Again the little boat of the church is shaken by the winds of ideology," Benedict said.
During Mass, Benedict bestowed the pallium, a woolen shawl, on 27 archbishops from around the world to symbolize their bond with the Vatican. The archbishops, wearing crimson vestments, knelt one-by-one before the pope to receive it.
The Orthodox delegation was sent by the spiritual leader of the world's 200 million Orthodox, Ecumenical Patriarch Bartholomew I, for the Mass marking the feast of St. Peter and St. Paul.
Benedict said he was grateful to Bartholomew "for this sign of fraternity that clearly shows the desire and commitment" to work for unity.
The Orthodox delegation was led by Metropolitan John Zizioulas, a leading Orthodox theologian.
Papal authority remains a key difference in efforts to bring Catholics and Orthodox closer together.
In a meeting with the Orthodox delegation after the Mass, Benedict described his role as "the first in the choir who has the task of maintaining the harmony of the voices."
He said their visit showed a common commitment "to eliminate all dissonance from the choir of the one church of Christ."
Benedict told them that the cooperation will be strengthened when he makes a scheduled trip in November to Turkey and visits Bartholomew at his headquarters in Istanbul.