Both churches must strive to return to their roots where they once "shared in the same eucharistic table, preserving together the same truths of faith while cultivating a variety of theological, spiritual and canonical traditions," the Pope said June 27 as he welcomed a delegation from the Ecumenical Patriarchate of Constantinople.
"That experience is a necessary point of reference and a source of inspiration for our efforts to restore full communion in our own day, a communion that must not be a bland uniformity," he said.
The delegation was in Rome for the celebration June 29 of the feast of Sts. Peter and Paul, the Vatican's patron saints.
Since 1969, the patriarchs have sent delegations to the Vatican each year on the feast of the Vatican's patron saints, and the popes have sent a delegation to Turkey each year for the feast of St. Andrew, patron of the patriarchate.
The feast of Sts. Peter and Paul, the Pope said, commemorates the martyrdom of two apostles who served God in different ways, yet "both bore witness to the merciful love of God our Father, which each in his own fashion profoundly experienced."
"It is right to celebrate together their self-sacrifice for love of the Lord, for it is at the same time a commemoration of unity and diversity," he said.
The traditional exchange of delegations, he added, "increases our desire for the full restoration of communion between Catholics and Orthodox."
Pope Francis also noted that this year marks the 50th anniversary of two meetings between Blessed Paul VI and Patriarch Athenagoras that led to the tradition of exchanging delegations on the feast days.
"The example of these courageous and farsighted pastors, moved solely by love for Christ and his church, encourages us to press forward in our journey toward full unity," Pope Francis said.
He also expressed his hope the September meeting of the coordinating committee of the Joint International Commission for Theological Dialogue between the two churches would take place in a "spiritual climate of attentiveness to the Lord's will" and fulfill Christ's prayer "for the unity of all his disciples."
"The fulfillment of this prayer is entrusted to God, but it also involves our docility and obedience to his will," Pope Francis said.