Ecumenism in the Catholic Church

Ruben Mendoza, 23 July 2026
The dome of St. Peter's Basilica. Image: Shutterstock

 

The SSPX controversy highlights competing visions of Christian unity, revisiting Vatican II’s teaching that ecumenism is essential to the Church’s mission and the search for full communion among believers.

“That they may be one” (Jn 17:21). This was the prayer of Jesus for all of those who believe in him.

Sadly, since his movement started, there have been divisions among his followers. Differences in beliefs created rifts among them. Some teachings were deemed heresies while others were labeled orthodox.

The first great schism in the one Church occurred between the Latin Church and the Church in the East. Then, further divisions arose, resulting in splits in the Latin Church between Roman Catholics and the different Protestant traditions.

Perhaps, in praying for the unity of his disciples, Jesus had an inkling of what would happen among them. Whatever he had in mind then, what is certain is that it is not God’s will that his followers are divided. It is actually scandalous. How can they effectively and credibly proclaim Jesus’ person and message when they are not in agreement about him?

That is why ecumenical dialogue is an integral part of the contemporary mission of the Church. The various Christian traditions are called to engage in dialogue and creatively imagine what unity means for and demands of them.

The World Council of Churches, “a fellowship of 356 churches from more than 120 countries, representing over 580 million Christians worldwide,” was established in 1948 for such a purpose.

The Catholic Church entered late into the picture. Ecumenism received official approbation only during the Second Vatican Council. Even then, not everyone in the Catholic Church accepted this teaching.

Among those who rejected the reforms of Vatican II, particularly ecumenism, was the Society of St. Pius X (SSPX), which has recently been in the limelight but for the wrong reason.

They decided to ordain new bishops without papal mandate on July 1; consequently, the consecrating bishops and the four newly consecrated bishops obtained automatic excommunication. It was a penalty that was affirmed by the Dicastery for the Doctrine of the Faith the following day.

In its profession of faith, SSPX asserts that Jesus Christ founded the “one Church, visible, hierarchical, indefectible, and necessary for salvation” (54), “One, Holy, Catholic and Apostolic” (55), “a visible society and the Mystical Body of Christ” (56), “the Immaculate Bride of Christ” (57), and “the Mother of souls” (58). They further “profess that God willed to make the Church the necessary means of salvation” (59), meaning that “no one can be saved without Christ and His Church, through a false religion as such, nor be assured of His salvation outside the visible structure of the Church” (60).

Given their exclusivist understanding of the Church and salvation, it is not surprising that they “reject false ecumenism, which rests upon the idea that the Holy Ghost would not refuse to use separated communities as means of salvation, as though the Church of Christ were present and active in them, or as though these communities possessed in themselves a salvific value whose efficacy would derive from the fullness of grace and truth entrusted to the Catholic Church” (61).

For them, true ecumenism is the return of other Christian traditions to the fold of the Catholic Church.

“We need the gift of the Spirit, the principle of the Church’s unity, to draw us closer to one another and overcome our differences”

In contrast to the SSPX’s position, Vatican II significantly changed the way Catholics understand those who belong to other Christian traditions.

It asserts that the one Church of Christ “subsists in the Catholic Church” and that “many elements of sanctification and of truth are found outside of its visible structure” (Lumen Gentium, 8). Vatican II further recognizes that the Church is linked with those who are not in full communion with Rome by virtue of their baptism, their use of Scripture, their belief in God the Father and in Christ, the celebration of the sacraments, and the Spirit’s operative sanctifying presence, who prompts all of God’s children to become one flock under one shepherd (Lumen Gentium, 15).

Furthermore, “This Vatican Council declares that the human person has a right to religious freedom” (Dignitatis Humanae, 2), in contrast to the pre-Vatican II position that error has no rights.

The Catholic principles of ecumenism in Vatican II are found in Unitatis Redintegratio (UR). The declaration affirms that Christ founded one Church and one Church only. That is why the Catholic Church seeks “the restoration of unity of all Christians”(1).

Significantly, UR asserts that “some and even very many of the significant elements and endowments which together go to build up and give life to the Church itself, can exist outside the visible boundaries of the Catholic Church: the written word of God; the life of grace; faith, hope and charity, with the other interior gifts of the Holy Spirit, and visible elements too. All of these, which come from Christ and lead back to Christ, belong by right to the one Church of Christ”(3).

In further contrast to the SSPX’s position, Vatican II teaches “that the separated Churches and Communities as such, though we believe them to be deficient in some respects, have been by no means deprived of significance and importance in the mystery of salvation. For the Spirit of Christ has not refrained from using them as means of salvation which derive their efficacy from the very fullness of grace and truth entrusted to the Church.”

At the same time, “it is only through Christ’s Catholic Church, which is ‘the all-embracing means of salvation,’ that they can benefit fully from the means of salvation” (UR 4).

Vatican II holds a special place for the Churches in the East, for they “possess true sacraments, above all by apostolic succession, the priesthood and the Eucharist, whereby they are linked with us in closest intimacy” (UR 15). It can’t be emphasized enough that the Orthodox Churches can trace their origin back to the apostles, just like the Catholic Church.

While Vatican II recognizes the Catholic Church’s close affinity with separated churches and ecclesial communities in the West, “there exist important differences from the Catholic Church, not only of a historical, sociological, psychological and cultural character, but especially in the interpretation of revealed truth” (UR 19).

The task of ecumenism is a gift. Given our stubbornness and our propensity to think of ourselves as better than we actually are, we need the Spirit of truth and humility to disturb and challenge our understanding of the truths of our faith.

We need the gift of the Spirit, the principle of the Church’s unity (Unitatis Redintegratio, 1), to draw us closer to one another and overcome our differences. We need to be like Mary of Bethany in not being worried and distracted by many things and in choosing the better part (Lk 10:41-42), which is our unity in Christ.

With thanks to Global Catholic and Ruben Mendoza, where this article originally appeared.

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