The Week of Prayer for Christian Unity will be celebrated by Catholics and other Christians worldwide from Jan. 18–25.

The theme for 2024, “You shall love the Lord your God ... and your neighbor as yourself,” is taken from the Gospel of Luke and selected by the Vatican’s Dicastery for Promoting Christian Unity, the Faith and Order Commission of the World Council of Churches, and the ecumenical community of Chemin Neuf in Burkina Faso. 

Each day of the weeklong celebration is centered on different Scripture readings and meditations, which can be found on the website of the Dicastery for Promoting Christian Unity. Other material prepared for the weeklong celebration includes the text for an ecumenical service, a historical overview, and key dates in ecumenical relations since the launch of the project. 

The internationally observed effort first started in 1908 under the leadership of Servant of God Father Paul Wattson, the founder of an Anglican religious community and later a convert to Catholicism. It was initially called the Octave of Christian Unity, with the approval of Pope Pius X, and was subsequently promoted by Pope Benedict XV. 

The octave is celebrated from Jan. 18–25 in the Northern Hemisphere and is typically observed around the feast of Pentecost in the Southern Hemisphere.

This year’s celebration also marks the 60th anniversary of the historic meeting between Pope Paul VI and Orthodox Ecumenical Patriarch Athenagoras I of Constantinople on the Mount of Olives in Jerusalem in 1964. That was the first formal meeting of a pope and ecumenical patriarch since 1438, marking a paradigm shift in the ecumenical relations between the Catholic and Eastern Orthodox Churches. 

On the 60th anniversary of the meeting in Jerusalem between Pope Paul VI and the Ecumenical Patriarch of Constantinople, Athenagoras I, we recall the landmark encounter through several images and the voice of the Holy Father.
Watch now: pic.twitter.com/m9tJlzsecr

— Vatican News (@VaticanNews) January 4, 2024

In 1965, the two leaders met in Rome, where they published the “Joint Catholic-Orthodox Declaration of His Holiness Pope Paul VI and the Ecumenical Patriarch Athenagoras I,” lifting the mutual excommunication between the churches from 1054. 

The document stated: “They likewise regret and remove both from memory and from the midst of the Church the sentences of excommunication which followed these events, the memory of which has influenced actions up to our day and has hindered closer relations in charity.” 

On Jan. 6, the feast of the Epiphany of the Lord, Pope Francis in his Angelus reflection said the anniversary marked a turning point in ecumenical relations between the Catholic and Orthodox Churches, which broke “a wall of incommunicability that for centuries had kept Catholics and Orthodox apart.” 

The Pope added: “And thinking of that historic gesture of fraternity in Jerusalem, let us pray for peace, for peace in the Middle East, in Palestine, in Israel, in Ukraine, all over the world. So many victims of war, so many deaths, so much destruction. Let us pray for peace.” 

On Jan. 25, the feast of the Conversion of St. Paul, Pope Francis will preside over the celebration of second vespers and deliver a homily at the papal Basilica of St. Paul Outside the Walls. The Holy Father will be joined by Archbishop Justin Welby of Canterbury, head of the Church of England.