What is the purpose of the Week of Prayer for Christian Unity?

This year, Christians across the world celebrate a special anniversary. 1,700 years ago, the Council of Nicaea, the first Ecumenical Council, was held following the end of the Roman persecutions. Such an anniversary heightens the necessity for the Week of Prayer for Christian Unity in 2025.

Every January 18^th, the Catholic Church begins a week of prayer, remembering the words of Jesus Christ in John’s Gospel where He asked the Father that Christians “may all be one”. Unfortunately, it is all too clear that this unity has not been achieved. It should be the hope of every Catholic that on this 1,700th anniversary of Nicaea, great gains be made in reconciling all non-Catholic Christians into the unity of Christ’s Mystical Body, the Catholic Church.

Unfortunately, however, many Catholics do not see a need to seek out our separated brethren. Many of our Catholic brethren, laity and ministerially ordained alike, do not see a need for non-Catholics who share a common baptism with us to enter into the divinely established and sole society that Christ founded, outside of which one cannot be sure of their salvation.¹ As the Second Vatican Council states in Lumen gentium: “Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved” (LG 14).

It is not, of course, for us to know who is culpable for this knowledge (only God is truly aware), but what we can discern is if someone is in visible union with the Church of Christ. If we see that someone is not in union with the Catholic Church, we have a duty to witness to the faith of our Fathers at the Council of Nicaea, and invite those non-Catholic Christians into the unity that Christ desired as his Passion loomed.

Certain Catholics would have it, though, that we only focus on our common baptism during the Week of Prayer; some going as far as to say that seeking out our separated Christian brethren to come into full Communion with the Church is not what this Week of Prayer is about, nor does the Second Vatican Council suggest as much. As some people have put it, the USCCB’s website on Ecumenism provides the real intention behind the Week of Prayer for Christian Unity. Indeed, an accurate summary of what Vatican II teaches is there, but the words of the Council can be misunderstood, distorted, or—as seen above in LG 14—outright ignored. This distortion and ignorance happen to such a great extent that continuity between what came before Vatican II and after it has been completely severed, and this certainly is seen to a great extent in the debate over what true ecumenism is.

But there is an answer to all this. As Pope St. Paul VI said when promulgating Lumen gentium in 1964 at the close of the Council’s third session:

There is no better comment to make than to say that this promulgation changes nothing of the traditional doctrine [on the Church]. What Christ willed, we also will. What was, still is. What the Church has taught down through the centuries, we also teach.

A few years later, in his General Audience of January 12, 1966, he reminded the faithful:

We must not detach the teachings of the Council from the doctrinal heritage of the Church, but rather see how they fit into it, how they are coherent with it, and how they bring testimony, increase, explanation, and application to it.

To not seek out our separated brethren would be foreign to men like St. Cyprian of Carthage, St. Augustine of Hippo, as it would to teachers later in history, such as St. Francis de Sales and St. Josaphat Kuntsevych. Therefore, we must recall why this Week of Prayer came into being in the first place, and recover its authentic meaning so that we can work towards a true and lasting reunion of all Christians to the Catholic Church throughout the rest of this year’s special anniversary of Nicaea.

Why was the date of January 18th chosen to start the Week of Prayer? This day was the traditional feast of the Chair of St. Peter at Rome, while the February 22^nd feast commemorated St. Peter’s Chair at Antioch. In the mid-20th century, the January feast was suppressed and combined with the February feast.

Consider what Pope Benedict XVI had to say in 2012 when the Week of Prayer opened. He observes that the task of true ecumenism, which is to reconcile all Christians to the one Church of Christ, “is a responsibility of the entire Church and of all the baptized, who must develop the partial communion that already exists among Christians and make it grow into full communion in truth and in charity.” He goes on, saying:

Of course, the fundamental truths of the faith unite us far more than they divide us. Yet the divisions remain, and also concern various practical and ethical issues, giving rise to confusion and diffidence, undermining our ability to transmit the saving word of Christ.

Yes, we have much more in common with non-Catholic Christians than we do with Muslims, Hindus, and others because of our shared baptism and shared profession that Jesus is the Incarnate God. But the divisions among us give a counter-witness to the world. Furthermore, many of our separated brethren find themselves without recourse to the life-giving sacraments.

With this in mind, the Week of Prayer for Christian Unity absolutely is all about seeking out our Christian brothers and sisters to come into full Communion with the Church. All the baptized must take part in the work of uniting all Christians to the one Church that Christ founded. Indeed, the Second Vatican Council’s Unitatis redintegratio most certainly suggests (and requires) this seeking out of our separated brethren. What is the “fullness of unity which Jesus Christ desires”? It is that all Christians may be one in His Mystical Body, which is the Catholic Church.

The USCCB’s Office for Ecumenical & Interreligious Affairs states that “Jesus Christ founded one Church and… prayed, ‘That they may all be one’ (John 17:21)”. In fidelity to Christ’s prayer, if we are to partake in the ecumenical movement—as the USCCB’s site states—we must seek visible unity among all Christians into the one and only visible Church that Christ established; that is, the Catholic Church. As the Office continues, “Ecumenical dialogue, the search for full, visible unity is thus essential to the Christian life.” The essential purpose of ecumenical dialogue is to repair the wounds of schism so that those not in union with Christ’s Mystical Body may return. This is precisely why every Catholic Christian should be taking part in this Week of Prayer, particularly through prayer and dialogue that does not paper over differences between the Catholic Church and other ecclesial communities.

Concerning this specific type of prayer, Catholics would do well to become acquainted with the original prayers that were composed and approved of by the Holy See when this Week of Prayer was initiated by Pope Benedict XV in 1916. In the prayer for the first day, the Church prays for St. Peter and the Blessed Virgin Mary to intercede before God in this way: “O Immaculate Virgin… look down with pity upon our separated brethren, who are still thy children, and call them back to the Center of Unity.” And later: “Strengthened by Divine Grace, may they be led back speedily to the bosom of our common Mother, the Catholic Church.”

As Pope Benedict XV said when he instituted this Week of Prayer:

[I]t is very important to Us that Christians who have sadly distanced themselves from the Catholic Church be invited to return to her… Therefore, in order that the desired goal may be more easily achieved, and that the above prayers may be recited everywhere to the great advantage of souls, We… will recite such prayers once a day every year, and then on the eighth day… have raised pious prayers to God for the… conversion of sinners and for the exaltation of Holy Mother Church.

Catholics in the United States recently took part in a National Eucharistic Revival. In fact, 2025 is the third and final year of this Revival, wherein all Catholics are to begin the work of restoring Eucharistic fervor in their own local communities among all Christians. If the Eucharist is the source and summit of Christian life, and so many of our separated brethren lack the Eucharist in their ecclesial communities, how could we in charity not seek them out to come into full communion with our Lord Jesus’ Catholic Church? The Eucharist is not optional. It is essential for the Christian life. Indeed, this is the week where we should all be seeking out our separated brethren boldly, yet charitably.

One might still object to all this, noting that the Second Vatican Council teaches that “elements [of the Church]… can exist outside the visible boundaries of the Catholic Church” (UR, 3). This fact is certainly true. But echoing Benedict XVI, the USSCB’s site reminds us that “A divided Christianity is a scandal to the world, and the movement of the Holy Spirit calls for the restoration of unity.” We are to be instruments of the Holy Spirit, and it is our task as Catholic Christians to respond to this movement of the Holy Spirit to restore union among all Christians with whom we share a common baptism. We must take the Second Vatican Council in context. This section quoted above from the Council’s Decree on Ecumenism finishes in this way: “All of these [elements and endowments], which come from Christ and lead back to Christ, belong by right to the one Church of Christ.” Where is that one Church of Christ?

As the Second Vatican Council also states in Lumen gentium, “This is the one Church of Christ which in the Creed is professed as one, holy, catholic and apostolic, which our Savior, after His Resurrection, commissioned Peter to shepherd… This Church constituted and organized in the world as a society, subsists in the Catholic Church, which is governed by the successor of Peter and by the Bishops in communion with him” (LG 8). This Church the Council speaks of admits of only a singular unit²; there is only “one Church of Christ”. And the way this society looks is that the people within the society are in union with, and “governed by”, Peter’s successors and “the bishops in communion” with that successor, the Pope of Rome. The one Church of Christ is identified explicitly by the Council as “the Catholic Church”. That same paragraph concludes by saying that “many elements of sanctification and of truth are found outside of its visible structure. These elements, as gifts belonging to the Church of Christ, are forces impelling toward catholic unity.” As observed in Unitatis redintegratio, elements of sanctification (like valid baptism) can be found outside the Catholic Church, but those gifts belong by right only to the Catholic Church.

This is something the Church has recognized since at least the time of St. Augustine. As the great saint once said, those outside the Catholic Church “have made their own private property out of what they have stolen from the Lord, and would feed not Christ’s flocks, but their own against Christ.”³ We see this same teaching brought forward again, in continuity, through the Second Vatican Council. Knowing all this, we see why it behooves us in Christian charity to lovingly seek out our separated brethren, encouraging them with “gentleness and reverence” (cf. 1 Peter 3:15-16) to return to the Church our Lord founded. That is how we can most perfectly maintain fidelity to Christ’s prayer “that they may all be one”. What a perfect week (and year) to work towards this realization!

Endnotes:

¹ Cf. Pope Pius XII’s Mystici Corporis Chrisiti, 103.

² See the Congregation for the Doctrine of the Faith’s Notification on the book “Church: Charism and Power” by Father Leonardo Boff O.F.M.

³ Sermon 96 on the New Testament, 2. For more on this subject from St. Augustine, see Letter 185, 10:46; On Baptism, Against the Donatists (Book IV), 17:25; Homily 3 on the First Epistle of John, 5.