“Today, in many parts of the world,
under the inspiring grace of the Holy Spirit,
many efforts are being made in prayer, word and action to attain
that fullness of unity which Jesus Christ desires.
The Sacred Council exhorts all the Catholic faithful to recognize
the signs of the times and to take an active
and intelligent part in the work of ecumenism.” (Unitatis Redintegratio, §4)

As Christians, we are all too familiar with the divisions that have plagued Christ’s followers since the very first days of Christianity and continue to this day.

Throughout the twentieth century, as the modern world became increasingly fractured and plagued by violence, Popes John XXIII and Paul VI saw that Christians should heed even more closely Christ’s call to be one as Christ is one with the with Father (Jn 17:21). If Christ says, in the Gospel of John, that the world would know that his followers were Christians because of their love for one another (Jn 13:35), the leaders of the Church saw how the bickering and the divisions between Christians marred their witness of Christ to the world. In a divided world, Christians ought to be a witness of the “one faith and one baptism” (Ephesians 4:4-6) they profess in Christ.

John XXIII and Paul VI, particularly, saw it was their responsibility, as Bishop of Rome, Successor of Peter, and Vicar of Christ on earth to try to follow Christ’s command to Peter to “feed my sheep,” and to care for the flock (Jn 21:17). Thus, these two popes worked hard to bridge centuries-old divisions between Christians. These popes (both canonized saints as of October 2018) advanced the unity of the Church worldwide. As pope, John XXIII established the Secretariat for Promoting Christian Unity which is today the Pontifical Council for Christian Unity. This branch of the Curia became the Roman Catholic Church’s representative in working with other Christians churches and ecumenical organizations.

John XXIII invited theologians from other Christian traditions to Vatican II as observers, such as George Lindbeck, a famous Lutheran American theologian. Opening up dialogue with other Christians led to continued dialogues with Orthodox, Lutheran, and Reform churches. Several of Notre Dame’s own theological faculty have been asked by the Vatican to serve on these dialogues, a great honor and responsibility. In 1999, the Lutheran World Federation and the Pontifical Council for Promoting Christian Unity jointly published the Joint Declaration on the Doctrine of Justification. This document was a milestone in Lutheran-Catholic relations, since many of Luther’s theological rallying cries during the Reformation, nearly 500 years before, centered around issues of justification (e.g., sola fide).

John XXIII’s successor, Paul VI, made a great leap in Christian and Orthodox relations by meeting with Ecumenical Patriarch Athenagoras I of Constantinople in 1964, in Jerusalem. Together, Paul and Athenagoras revoked millennium-old excommunications that had been mutually invoked upon their respective churches. Tantur Ecumenical Institute, which houses Notre Dame’s Jerusalem Global Gateway, was built to honor this meeting. The Vatican has entrusted to Notre Dame the responsibility for caring for and maintaining this important property, which is built to help Christians truly seek unity through the study of Scripture, discussion and prayer together.

Two important Church teachings regarding Christian Unity and Christian Ecumenism are Unitatis Redintegratio, “Restoration of Unity,” and Ut Unum Sint, “That they may be one.” Unitatis Redintegratio was a decree drafted by the bishops during the Second Vatican Council and officially promulgated by Paul VI on November 21, 1964. Ut Unum Sint is an encyclical letter by Pope John Paul II, published in May 1995, on the Church’s commitment to ecumenism. Both documents urge Christians to work for peace and Christian Unity by healing divisions.

As we mourn the deep divisions in our nation, our Church, and our world, the witness of Christian charity in unity becomes all the more important. Our divided and conflicted world is full of men and women sorely in need of the light and truth of the Gospel.
The image above is of the Church of the Holy Sepulchre in Jerusalem, which is divided between six branches of Christian churches. It is a sign both of our unity in the mystery of Christ’s death and resurrection and in the brokenness of our communion with one another.

On this opening day of the Week of Prayer for Christian Unity, may we work to heal divisions between all Christians, so that we may all be truly one in Christ!