How Visible Should Christian Unity Be?


The priestly prayer of the Lord Jesus in John 17 is unanimously recognized as one of the foundational texts, if not the text par excellence, in dealing with Christian unity. There our Lord prays to the Father for His disciples to be one and the pattern of their unity is the relational life of the Trinity. As Father and Son are one, so Christians are prayed for so that their unity will be “as” the Triune God is one.

The consensus is shaken and eventually broken when different Christians spell out what this unity should be and how it should be lived out. One of the contentious issues revolves around this unity being “visible”. The fact that Christian unity should be somewhat visible is not what is at stake. What kind of “visibility” is required by the Lord’s prayer is where Christians begin to disagree.

In his address to participants at the plenary Assembly of the Pontifical Council for Promoting Christian Unity (15th November 2012), Pope Benedict XVI restated the basic Roman Catholic idea concerning the necessary visibility of Christian unity: “We must not forget that the goal of ecumenism is the visible unity among divided Christians”. The Pope later explained that “it is in full communion in faith, in the sacraments and in the ministry, that will become concretely evident the present and active power of God in the world”. Visibility is therefore a threefold achievement whereby there is unity in the profession of the faith, unity in the celebration of the sacraments, and unity in the recognition of the same ministerial order.

Does John 17 Support the Fully Orbed Roman Catholic View of Unity?

The same conviction was argued for by Cardinal Kurt Koch, President of the Pontifical Council for Promoting Christian Unity, in a recent public lecture at the Pontifical Lateran University (11th December 2012) entitled “Unity: Illusion or Promise?”. The lecture was a learned commentary on John 17 which Cardinal Koch divided in six parts. According to John 17 as it was read by Koch, Christian unity has six dimensions: spiritual, visible, Trinitarian, eschatological, missional, and martyrological (i.e. the unity of Christian martyrs).

What is of interest here is that Koch insisted on the visible dimension of the unity for which Jesus prayed and which he rooted in the Trinitarian life. Since the Church is “the icon of the Trinity” so her unity reflects the unity of the Trinity. Koch underlined the fact that Christian unity cannot be “invisible” but should always be recognizable in the usual threefold way: common profession of faith, common sacraments, common ministry. In other words, in order for unity to be Trinitarian unity you need the Roman Catholic Church that has kept the sacraments in their integrity and has transmitted the ministry in the proper apostolic succession. The visibility of the Trinitarian unity requires and demands the institutional (Roman Catholic) church, its hierarchy, and its sacramental life. In this view, other visible forms of Christian unity are imperfect and partial because they lack the (Roman Catholic) sacraments and ministry. According to this view, the visibility of unity will be achieved when other churches and ecclesial communions embrace not only the common profession of faith, but also the Roman Catholic sacraments and priesthood.

Does this understanding of the visibility of unity derive from Trinitarian life as it is found in John 17? It is hard to read this chapter and conclude that the reference to the Trinity as the pattern for Christian unity refers to a hierarchical and sacramental ministry. The latter seem added

dimensions which are quintessential to the Roman Catholic understanding of unity, but are difficult to trace back to Trinitarian life per se.1

A More Biblically Realist View of Visible Unity?

As I was listening to Cardinal Koch, another reading of John 17 as the basis of Christian unity came to my mind. I recalled the 1962 sermons on the passage by Martyn Lloyd-Jones (1899-1981) which were later published.2 The contexts between Koch and Lloyd-Jones are very different, yet the comparison is evocative. From Jesus’ priestly prayer, Lloyd-Jones argues that unity embraces those who are given to Jesus by the Father by believing in Him. First and foremost, unity is unity of those who are believers in Jesus Christ (17:6-10), not unity of the baptized as the ecumenical understanding would suggest. One can be baptized and yet not be a believer. Christian unity applies to the latter, not necessarily to the former.

According to Lloyd-Jones’ reading of the passage, Christian unity starts within and then works outward. It is primarily unseen and internal, although it manifests itself visibly. The Trinitarian foundation speaks about the depth and scope of this union, but it does not spell out any given institutional path in which it is bound to express itself.

This interpretation of the text indicates that neither a particular form of apostolic succession nor a particular sacramental and hierarchical system can be derived from the Trinity itself as if it were the only or the absolute or the perfect pattern for Christian unity. Unity is based on the truth of the Word of God (17:16) and is aimed at witnessing to the world (17:21). The visibility of the unity, as important as it is, depends on the spiritual reality which is a reflection of the Trinitarian life and is above all a gift for the believers in Jesus Christ so that others too would come to Him.

As an aside, Cardinal Koch’s lecture was followed by a prayer for Christian unity with a final intercession to Mary and by a song entitled “Mary, You Are our Mother” which said “… you (Mary) are our Advocate … Queen of Peace”. Even in this ecumenical event, there was no apology for deeply felt convictions. Roman Catholic ecumenism is not about reducing the claims of Catholicism but is a way of implementing them.

Leonardo De Chirico

Rome, 12th December 2012


1 The attempt to read back in the Trinity a particular view of the church (and therefore of her visible unity) is widespread. In his book After Our Likeness. The Church as the Image of the Trinity (Grand Rapids, MI: Eerdmans, 1998) Miroslav Volf talks about the fact that Zizioulas, Ratzinger and himself claim that their respective ecclesiology derives from the Trinity.

2 The Basis of Christian Unity. An Exposition of John 17 and Ephesians 4 (London: Inter-Varsity Press, 1962).

About the author

Chris Castaldo (PhD, London School of Theology) is the lead pastor at New Covenant Church in Naperville, Illinois. He is the author of Talking with Catholics about the Gospel and coauthor of The Unfinished Reformation.


  1. Thank you for this article.

    I agree that Christian Unity has to do with the fellowship of disciples who are all branched to the one vine, who is our Lord, and who “believe” (John 3:16) and who “bear fruit” (John 15:1-5). But something that needs to be asserted here is that the Catholics do not view professing Christians who are inwardly and in reality not truly following Christ as “unbelievers”.

    This is a Evangelical caricature. Let’s receive counsel from the Bishop James of Jerusalem, a man can have “faith” either if he has good works or if he does not have good works. Demons have “faith”, but they do not have good works. Therefore, demons are believers who do not have good works. People who obtain salvation have “faith”, but they have good works with their faith. Therefore saved people are believers who do have good works. Therefore, the evangelical dichotomy between a true believer and a unbeliever is not a biblical notion whatsoever, in any sense. In James, it is believing together with working that established the certainty of salvation. Believing without working does not save anyone, because believing alone is tantamount to the demonic.

    Even within evangelical baptist circles, the Church has in it’s community believers and Christians, some will be saved and others will not. It is not as though there is a fixed number of “true” believers and unbelievers, although each and everyone confesses the same belief. They are all validly Christians and believers, but this does not guarantee salvation.There is the possibility of having “believed in vain”, which does not deny the act of believing in any sense (1 Corinthians 15:1-4).

    Secondly, if we compare the host of protestant denominations who are at great disagreement with each other and exercise excommunication on each other, this can hardly be a picture of the unity that Christ prayed for in John 17.

    But let’s say that the unity here prayed for is not doctrinal in a dominant sense, but more to do with the internal transformation and fellowship that born again believers have with each other when they get together and love one another and by their mutual faith produce fruit to each others account. This may happen in one local church here and there. But this does not exist on a large scale between professing Christians.

    I have known and experienced an excommunication between two of the same kind of Church: 2 Baptist Churches. I have seen excommunication from evangelical churches who view themselves as “truly” evangelical and separate from “false” evangelical churches. I’ve seen great unity in one protestant church and then immediate disunity over doctrine or leadership.

    Most Churches who take serious the commands of Christ recognize that they are responsible to erect dividing lines between what they consider to be “true” fellowship and “sinful” fellowship. Each evangelical protestant Church has it’s own idea and interpretation, and the worst part about it is that there is always an opening for change in doctrine. Now I don’t want to discredit the traditions in protestant circles which do keep very good doctrine.

    Now this is not to say there is perfect unity even within Orthodox, Anglo-Catholic, or Roman Catholic churches either. However, there is a unity in the confession which sets the stage for that unity which is in Spirit and love. In protestant circles, you have the Calvinist who condemnds the Arminian, and vice versa. King James Only controversies. Free Will Baptist versus Particular Baptists. All the divisions in the Presbyterian circles. The list goes on and on.

    There is no perfect church. In the Catholic Church, the evangelical protestant who is on fire for good works, bible study, corporate evangelism, open-air preaching, etc,etc is going to have a hard time flourishing in these fields and finds himself thinking everyone is lost because they do not have the fire in their bones and the obedience of Christ. The Catholic goes into the protestant circle and sees the thousands upon thousands of different ideas, condemnations, excommunications, separations, etc,etc and it leads him/her into questioning God altogether.

    We remain today as people who pray for unity.

  2. “The Center for the Study of Global Christianity (CSGC)
    at Gordon-Conwell Theological Seminary … obtained denominational membership information from about 41,000 organizations worldwide.”

    In North America alone, there are 21 Presbyterian divisions:

    1. Associate Reformed Presbyterian Church
    2. Bible Presbyterian Church
    3. Covenant Presbyterian Church
    4. Cumberland Presbyterian Church
    5. Evangelical Assembly of Presbyterian Churches in America
    6. Evangelical Covenant Order of Presbyterians
    7. Evangelical Presbyterian Church (United States)
    8. Evangelical Reformed Presbyterian Church
    9. Free Presbyterian Church of North America
    10. Orthodox Presbyterian Church
    11. Presbyterian Church (U.S.A.)
    12. Presbyterian Church in America
    13. Presbyterian Church in Canada
    14. Presbyterian Reformed Church (North America)
    15. Reformed Presbyterian Church General Assembly
    16. Reformed Presbyterian Church in the United States
    17. Reformed Presbyterian Church of North America
    18. Reformed Presbyterian Church – Hanover Presbytery
    19. United Presbyterian Church of North America
    20. Upper Cumberland Presbyterian Church
    21. Westminster Presbyterian Church in the United States

    However, the very definition of the word Presbyterian [adj.
    1. Of or relating to ecclesiastical government by presbyters] even implies a single government. When will these Presbyters release their grip on their fiefdoms and allow their members and assets to at least return to a single Presbyterian denomination as Calvin and Knox envisioned?

    That there are approximately 41,000 distinct Protestant denominations is a scandal to Christ’s High Priestly Prayer any way you slice the data.

  3. Yes,

    But I think we should be careful in attributing automatic damnation to separated brethren. Some Catholics have left the Catholic faith because in their own lifetime they have not seen the transforming power of the gospel and when they go to a protestant church, they see people on fire for the Lord.

    Only if they realized that it would be just as possible to grow up in a dead catholic church as there is to go through 40 years of dead evangelical churches, they would study the doctrine more than simply go by what they see.

  4. The church of God is one, but because of our human nature, God permissive will allows us to have it the way it is now.

    If can learn to allow the Holy Spirit to take full charge of His church then things will be different.

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