Pope Francis said Wednesday that the full restoration of communion among all Christians is “an urgent priority in today’s world.”

In a letter to the Ecumenical Patriarch Bartholomew I of Constantinople, the pope expressed gratitude that Catholic and Orthodox Christians are seeking “to achieve full communion that will enable us one day, in God’s time, to gather together at the same eucharistic table.”

“The full restoration of communion among all the believers in Jesus Christ is an irrevocable commitment for every Christian, for the ‘unity of all’ (Liturgy of St. John Chrysostom) is not only God’s will but an urgent priority in today’s world,” Pope Francis said on Nov. 30.

The pope’s letter marked the feast of St. Andrew. Pope Francis sends a message each year on the feast to the Ecumenical Patriarch, who is regarded as the successor of St. Andrew the Apostle and “first among equals” in the Eastern Orthodox Church.

In this year’s letter, Pope Francis wrote that Christians are called to work toward the restoration of unity “not merely through signed agreements but through fidelity to the Father’s will and discernment of the promptings of the Spirit.”

“Much attention has rightly been placed on the historical and theological reasons at the origin of our divisions. This shared study must continue and develop in a spirit that is neither polemical nor apologetic but marked instead by authentic dialogue and mutual openness,” Pope Francis said.

“We must likewise acknowledge that divisions are the result of sinful actions and attitudes which impede the work of the Holy Spirit, who guides the faithful into unity in legitimate diversity. It follows that only growth in holiness of life can lead to genuine and lasting unity.”

Patriarch Bartholomew expressed support earlier this month for finding a common date for Easter, a move that would lead to Catholics and Orthodox celebrating the Resurrection of Jesus Christ at the same time.

The patriarch said that conversations are underway between Church representatives to come to an agreement. According to an earlier report by Vatican News, the patriarch supports such a common date to be set for the year 2025, which will mark the 1,700th anniversary of the First Ecumenical Council of Nicea.

The Holy See press office reported on Nov. 30 that a Vatican delegation traveled to Istanbul for a customary visit to the Ecumenical Patriarchate for the feast of St. Andrew.

Cardinal Leonardo Sandri, prefect emeritus of the Dicastery for the Eastern Churches, led the delegation, which included the undersecretary for the Dicastery for Promoting Christian Unity, Msgr. Andrea Palmieri. They were joined by Archbishop Marek Solczynski, the apostolic nuncio to Turkey.

The delegation took part in a solemn Divine Liturgy presided over by Patriarch Bartholomew in St. George’s Cathedral in Istanbul, where Sandri read the pope’s letter aloud.

“Invoking upon you Almighty God’s gifts of serenity and joy, I renew my expression of good wishes for the feast of St. Andrew, and exchange with Your All Holiness a fraternal embrace of peace in the Lord,” Pope Francis said.