Michelangelo Buonarroti - The Holy Family, Galleria degli Uffizi, Florence, Italy, 1505.

"Holy Father, keep them in your name that you have given me,
so that they may be one, just as we are."
Gospel of John 17:11

"May the God of endurance and encouragement grant you to think in harmony with one another, in keeping with Christ Jesus, that with one accord you may with one voice glorify the God and Father of our Lord Jesus Christ."
Epistle of St. Paul to the Romans 15:5-6

"I urge you, brothers, in the name of our Lord Jesus Christ, that all of you agree in what you say, and that there be no divisions among you, but that you be united in the same mind and in the same purpose."
First Letter of St. Paul to the Corinthians 1:10

"I, then, a prisoner for the Lord, urge you to live in a manner worthy of the call you have received,
with all humility and gentleness, with patience, bearing with one another through love, a striving to preserve the unity
of the spirit through the bond of peace: one body and one Spirit, as you were also called to the one hope of your call;
one Lord, one faith, one baptism; one God and Father of all, who is over all and through all and in all."
Letter of St. Paul to the Ephesians 4:1-5


The third Millennium is a time to restore Christian unity, as in the times of Jesus. Christian unity was the prayer of Jesus (John 17:11 and 17:21) and the plea of St. Paul, the Apostle to the Gentiles, throughout his Epistles. 1

History has recorded divisions within the Church of Jesus Christ. The teaching of the Council of Ephesus in 431 (on Mary as Mother of God) was not accepted by the independent Church of the East in Persia.2 Those that believed that Jesus was one incarnate nature of the Word of God formed the Oriental Orthodox Churches, for they did not accept the teaching of the Council of Chalcedon in 451, that Jesus was one Person with two natures, Divine and human in perfect harmony. A major split occurred during the Schism of 1054 between the Byzantine Orthodox of Constantinople and the Catholic Church of Rome.3 The Protestant Reformation that began with Martin Luther in 1517 constituted the major division in the West.

This lack of Christian unity proved to be a grave impediment to bringing non-Christians into the Church. The loss of Christian unity led to the secularization of Western culture. Recognition of this problem served as an impetus toward Christian unity among the Protestants in the early twentieth century, beginning with the World Missionary Conference of Edinburgh in 1910, and the formal organization of the World Council of Churches in 1948. The call for Christian unity accelerated with the surprise announcement of Pope John XXIII for the Second Vatican Council on January 25, 1959. Pope John Paul II made great efforts to continue the ecumenical movement throughout his Papacy. 4

As we are familiar with the Catholic approach to Christian unity, this paper will focus primarily on the ecumenical efforts of the Second Vatican Council and Pope John Paul II.

Bartolome Esteban Murillo - Jesus gives John the Baptist drink from a shell, El Prado, 1670.


The surprise announcement of a Second Vatican Council by Pope St. John XXIII was welcomed with open arms by all of Christianity, for the Pope called not only for "an intense spiritual cultivation" of the modern world, but also sought Christian unity. 5

His opening speech convening the Second Vatican Council on October 11, 1962 referred to Jesus in the Gospel of John (17:11): "The Catholic Church, therefore, considers it her duty to work actively so that there may be fulfilled the great mystery of that unity, which Jesus Christ invoked with fervent prayer from His heavenly Father on the eve of His sacrifice." 6

The Pope then stressed the need for unity in three areas: namely, the unity of Catholics among themselves; the unity with those Christians separated from our Church, and unity in dignity for those who follow non-Christian religions.

The Second Vatican Council literally "reset the course" for the Catholic Church, a Church which had been described by some as a fortress embattled by events of the world outside. The reforms of the Council of Trent begun in 1545 were necessary following the Protestant Reformation. To coin the expression of Hans Urs von Balthazar in 1952, the time had come to "raze the bastions" of the Church.7 It was time for the aggiornamento of Pope John XXIII, the "opening of the window" of the Church to the outside world, "a translation of the Christian message into an intellectual language understandable by the modern world." 8

The landmark Council convened from October 1962 to December 1965 and was attended by over 2000 Catholic Bishops and representatives from major Christian denominations from all over the world. Pope John XXIII presided over the first session in 1962 before his untimely death on June 3, 1963, but his work was ably continued by Pope Paul VI.

Sixteen documents were published throughout the Council. There were four principal Constitutions: the Constitution on the Sacred Liturgy, Sacrosanctum Concilium; the Dogmatic Constitution on the Church, Lumen Gentium; the Dogmatic Constitution on Divine Revelation, Dei Verbum; and the Pastoral Constitution on the Church in the Modern World, Gaudium et Spes. There were also nine Decrees - the Decree on the Eastern Catholic Churches, Orientalium Ecclesiarum; the Decree on Ecumenism, Unitatis Redintegratio; the Decree on the Mission Activity of the Church, Ad Gentes; the Decree concerning the Pastoral Office of Bishops in the Church, Christus Dominus; the Decree on Renewal of Religious Life, Perfectae Caritatis; the Decree on the Ministry and Life of Priests, Presbyterorum Ordinis; the Decree on Priestly Training, Optatam Totius; the Decree on the Apostolate of the Laity, Apostolicam Actuositatem; and the Decree on the Means of Social Communication, Inter Mirifica. There were three Declarations: the Declaration on Religious Freedom, Dignitatis Humanae Personae; the Relation of the Church to non-Christian religions, Nostra Aetate; and the Declaration on Christian Education, Gravissimum Educationis. 9

This paper will briefly outline the four major Constitutions of Vatican II, the Declaration on Religious Liberty, and the Decree on Ecumenism, as well as the encyclical That All May Be One by Pope John Paul II.


The first document produced by the Second Vatican Council was the Constitution on the Sacred Liturgy, Sacrosanctum Concilium, published on December 4, 1963. The opening sentence of the document clearly expressed the purpose of Vatican II: "This sacred Council has several aims in view: it desires to impart an ever increasing vigor to the Christian life of the faithful; to adapt more suitably to the needs of our own times those institutions which are subject to change; to foster whatever can promote union among all who believe in Christ; to strengthen whatever can help to call the whole of mankind into the household of the Church."

The most visible changes noted in the Church spring from this Constitution. The liturgy of the Mass may be said both in the traditional Latin Tridentine Mass and may also be said in the native language. The Tridentine Mass preserves the same liturgy for all nations and all ages, for it is said in Latin, the universal language for the universal Church. The Mass in the native (or vernacular) language allows the liturgy to be intelligible to the layman and helps secure their participation to the fullest. The presence of Christ in the Liturgy was emphasized. Sermons are to reflect Scripture and the prayers of the faithful are renewed. RCIA (Rite of Christian Initiation for Adults) was renewed, and Extreme Unction, the Sacrament once reserved for the terminally ill, is now called the Anointing of the Sick, to reflect its use for the seriously ill.


The central document to the Second Vatican Council is the Dogmatic Constitution on the Church, Lumen Gentium, the "Light of Nations". The Constitution was promulgated by Pope Paul VI in the third year of the Council on November 21, 1964. Pope John Paul II, on World Mission Day in 1992, called Lumen Gentium the keystone of the Council's whole Magisterium, for with this document, the Council "wished to shed light on the Church's reality." Contained within the document are concepts that are central and form the basis for most of the other documents of Vatican II.

"Christ is the Light of Nations."

The opening sentence of Lumen Gentium (LG) places the Church at its very point of origin, Jesus Christ.

A Spirit of Christian Unity

The charismatic spirit evident at the Council led to the hope and effort for Christian unity. In addition to Lumen Gentium, Christian unity or ecumenism was also the theme of the Decree on Eastern Catholic Churches, Orientalium Ecclesiarum, which called for unity of Catholics among themselves; and the Decree on Ecumenism, Unitatis Redintegratio. All three articles were published the same day, November 21, 1964.

The Second Vatican Council treated the "one, holy, catholic, and apostolic" church as the Church of Jesus Christ, and did not isolate those attributes to the Roman Catholic Church alone. Article 8 of Lumen Gentium opened the door for all Christian Churches to become one, when it declared that the one Church of Jesus Christ subsists in the Catholic Church, but that many elements of sanctification and truth are found outside of its visible structure: 10

"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, although 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." (LG 8)

Lumen Gentium called all to become one "People of God." Ecumenism is further encouraged by the strong Scriptural foundation of the Constitution on the Church, as the Bible, especially the New Testament, is a common bond with our brethren, the Orthodox and the Protestants. 11

The role of the hierarchy of the Church is defined as one of service, and collegiality of the Bishops in union with the Pope as leader is stressed. For the first time ever in the history of the Church, the role of the laity in the Church was outlined. Emphasis is placed upon the eschatological importance of the religious with their vows of poverty, chastity, and obedience, for they serve as models to the modern world - a world obsessed with materialism, sex, and rebellion to authority. Mary and the communion of saints point to our ultimate hope and dream of a life eternal with our Heavenly Father, his Son Christ Jesus, and the Holy Spirit.


This Constitution, Dei Verbum, published November 18, 1965, asserted unequivocally the historicity of the Gospels, and the confirmation that Tradition and Scripture form one deposit of faith, and interpretation of the Bible ultimately rests with the Magisterium or Teaching Office of the Church. The Council stated the following concerning inspiration and interpretation of Scripture:

"Those divinely revealed realities which are contained and presented in Sacred Scripture have been committed to writing under the inspiration of the Holy Spirit," and thus teach "without error that truth" necessary for the sake of our salvation. Thus Holy Scripture must be read and interpreted in the sacred Spirit in which it was written," in the light of Faith. We must be attentive "to the content and unity of the whole of Scripture, keeping in mind the living tradition of the whole Church and the analogy of faith."

The Council stressed the importance of Sacred Scripture in the life of the Church, for all preaching in the Church must be nourished and regulated by Sacred Scripture. 12


The December 7, 1965 Pastoral Constitution Gaudium et Spes was unique in that this final document of Vatican II sprung up on the Council floor, for this was indeed the very essence of the Council - the role of the Church in the modern world. The opening lines reflect its identity with all men - "the joys and hopes, the griefs and the anxieties of the men of this age, especially those who are poor or in any way afflicted, these are the joys and hopes, the griefs and anxieties of the followers of Christ."

Gaudium et Spes is realistic but offers hope in the light of Christ and the dignity of man. In fact, Pope John Paul II in 1995, the thirtieth anniversary of its publication, called Gaudium et Spes "the Constitution of life and hope." The mission of the Church is one of service and support, to transform the world in the light of the Gospel.

Part One has a similar structure to all its chapters - they lay out a specific problem and find the solution in Jesus Christ. Part One addresses the dignity of the human person, the community of mankind, and man's activity in the world. Part Two offers discussion of specific problems, and the need to preserve the dignity of man in the light of Christ in the following settings - marriage and the family, culture, economics, politics, and peace. 12

The Constitution reaffirms the Church's emphasis on social justice, first expressed in the landmark papal encyclical Rerum Novarum by Pope Leo XIII in 1891.13 Gaudium et Spes calls for the common good, that is, "the sum of those conditions of social life which allow social groups and their individual members relatively thorough and ready access to their own fulfillment" (26). 14

Three famous quotations from Gaudium et Spes follow:

"The truth is that only in the mystery of Jesus Christ does the mystery of man take on light" (22).

"Man, who is the only creature on earth which God willed for itself, cannot fully find himself except through a sincere gift of himself" (24).

"Christ, to be sure, gave His Church no proper mission in the political, economic or social order.
The purpose which He set before her is a religious one. But out of this religious mission itself come a function, a light and an energy which can serve to structure and consolidate the human community according to the divine law" (42).15


Dignitatis Humanae Personae, the Declaration on Religious Freedom, passed the Council on December 7, 1965. It has sometimes been called the American contribution to the Council, for it emphasizes the ideal of religious freedom, as noted in the First Amendment of the Bill of Rights of the United States Constitution. The Declaration is a landmark document in that it shows a significant development in the Church's attitude toward religious freedom. The Vatican declared that the human person has a right to religious freedom, and its foundation lies in the very dignity of the human person, the actual translation of the first words of the Declaration. Reflecting Pacem in Terris, the April 1963 encyclical of John XXIII, man is bound to seek the truth and follow his conscience faithfully, "so that he may come to God, who is his last end." This free exercise of conscience and religion is to be free from coercion, provided the just requirements of public order are not violated. The Declaration recognizes the reality of the modern world, in which people of various faiths live together, and expresses the awareness that religious liberty is an essential concern of the Church and society. 16


The Vatican II Decree on Ecumenism, Unitatis Redintegratio (UR), is directed to unity with our Christian brothers, such as the Orthodox or the Protestants. The Decree on Ecumenism opens in Article One with the call for unity:

"The restoration of unity among all Christians is one of the principal concerns of the Second Vatican Council. Christ the Lord founded one Church and one Church only. However, many Christian communions present themselves to men as the true inheritors of Jesus Christ; all indeed profess to be followers of the Lord but differ in mind and go their different ways, as if Christ Himself were divided. Such division openly contradicts the will of Christ, scandalizes the world, and damages the holy cause of preaching the Gospel to every creature."17

Definition of Ecumenism

The Introduction (Article One) of the Decree on Ecumenism then defines ecumenism as a movement, fostered by the grace of the Holy Spirit, for the restoration of unity among all Christians. Taking part in this movement are those who invoke the Triune God and confess Jesus as Lord and Saviour. The principle of unity is the Holy Spirit (UR-2).

A Change of Heart

Perhaps the most noticeable difference since Vatican II is the change of heart within the Catholic Church towards Orthodox and Protestants. The Spirit of Vatican II has led to an openness to our Christian brethren. For men who believe in Christ and have been truly baptized are in communion with the Catholic Church even though this communion is imperfect. "It remains true that all who have been justified by faith in Baptism are members of Christ's body, and have a right to be called Christian, and so are correctly accepted as brothers by the children of the Catholic Church" (UR-3).

Pope John Paul II, in his 1994 bestseller Crossing The Threshold of Hope, rightly observed that "the Second Vatican Council differed from earlier councils because of its particular style. It was not a defensive style. Not once in the Council documents do the words anathema sit appear. It was an ecumenical style, characterized by great openness to dialogue." 18

The Decree outlines a practical approach for the ecumenical movement to promote Christian unity. First, every effort must be made to avoid expressions, judgements, and actions which do not represent the condition of our brethren with truth and fairness. Second, a dialogue between competent experts from different Churches should be organized in a religious spirit to explain the teaching of his Communion to bring out its distinctive features. Third, Christians can cooperate for the common good, such as the pro-life movement. Fourth, prayer in common should be encouraged. Fifth, all are led to examine their own faithfulness to Christ's will for the Church "to undertake with vigor the task of renewal and reform" (UR-4). Sixth, Catholics should "become familiar with the outlook of our separated brethren," and acquire a more accurate understanding of their respective history, doctrines, spiritual and liturgical life (UR-9). An openness to their thought may lead to our own edification. And seventh, instruction in sacred theology, history, and other branches of knowledge must be taught with due regard for the ecumenical point of view (UR-10).

It is hoped that this approach will create a "spirit of brotherly love and unity," in order that the goal of ecumenism be attained: "all Christians will be gathered, in a common celebration of the Eucharist, into the unity of the one and only Church, which Christ bestowed on his Church from the beginning" (UR-4).

One aspect we cannot forget is a life of Christian witness and example to others. "Every Catholic must therefore aim at Christian perfection" (UR-4). For "there can be no ecumenism worthy of the name without interior conversion" (UR-7). The Decree on Ecumenism calls this change of heart and holiness of life, along with public and private prayer for the unity of Christians the soul of the whole ecumenical movement, and merits the name spiritual ecumenism (UR-8). 19


The Decree on Ecumenism presents important guidelines in dialogue with our Christian brethren. While it is essential that the doctrine should be clearly presented in its entirety, "nothing is so foreign to the spirit of ecumenism as a false irenicism, in which the purity of Catholic doctrine suffers loss and its genuine and certain meaning is clouded" (UR-11).

The Decree on Ecumenism emphasizes that, in dialogue with our brethren, Catholic theologians should remember that in Catholic doctrine there exists a hierarchy of truth, since they vary in their relation to the fundamental Christian faith (UR-11).

Another important consideration is that there may be differences in theological expression of doctrine (UR-17), for example, as seen with the Eastern Christian Churches. However, the Decree concludes that in such cases, these various theological expressions are to be considered often as "mutually complementary rather than conflicting" (UR-17). An example where this concept may apply is the filioque clause in the Nicene Creed.

The Divine Mercy of Jesus.


Pope St. John Paul II, who died April 2, 2005, continued the work of Christian unity begun with Pope John XXIII and the Second Vatican Council. His message, first evident in his contribution to the Vatican II document, the Pastoral Constitution on the Church in the Modern World, has been consistent, that the answer to man's dignity and very identity in the modern world rests in Jesus Christ.

Pope John Paul II, in his March 25, 1995 encyclical That All May Be One - Ut Unum Sint, addresses the common bonds among all Christians, with our Orthodox and Protestant brethren. He emphasizes our common bonds of unity in faith in Jesus Christ our Savior, Son of God the Father, who sent the Holy Spirit; Baptism; the New Testament of the Bible; and prayer, especially the Lord's Prayer, the Our Father.

St. Pope John Paul II again calls for spiritual ecumenism. The Pope continues - "Love gives rise to the desire for unity, even in those who have never been aware of the need for it. Love builds communion between individuals and between communities" (UUS 21 - Ut Unum Sint, Article 21).

He also directly addressed those areas of study before a true consensus of faith can be achieved: "(1) the relationship between Sacred Scripture, as the highest authority in matters of faith, and Sacred Tradition, as indispensable to the interpretation of the Word of God; (2) the Eucharist, as the Sacrament of the Body and Blood of Christ, an offering of praise to the Father, the sacrificial memorial and Real Presence of Christ and the sanctifying outpouring of the Holy Spirit; (3) Ordination, as a Sacrament, to the threefold ministry of the episcopate, presbyterate, and diaconate; (4) the Magisterium of the Church, entrusted to the Pope and the Bishops in communion with him, understood as a responsibility and an authority exercised in the name of Christ for teaching and safeguarding the faith; (5) the Virgin Mary, as Mother of God and Icon of the Church, the spiritual Mother who intercedes for Christ's disciples and for all humanity" (UUS 79). 20


The call for Christian unity in the twentieth century was a watershed event for Christian Churches, and could not have been more timely. While Christians have fought among themselves for centuries over theological differences, secular humanism and materialism have swept the globe, and threaten to eradicate religion itself, especially among the young. This is a time we Christians must be united in our spread of the Gospel of Jesus Christ in the face of secularism and atheism.

We must continue this effort as we enter the new millennium. As Pope John Paul II urges us in Tertio Millennio Adveniente, the "Church should invoke the Holy Spirit with ever greater insistence, imploring from him the grace of Christian unity." We must pray for unity, for "unity is a gift of the Holy Spirit." 21

Christian unity will be achieved when all believers open their hearts to Christ Jesus and to each other.

"Is not the cup of blessing which we bless a sharing in the blood of Christ?
Is not the bread which we break a sharing in the body of Christ?
Since there is one bread, we who are many are one body;
for we all partake of the one bread.
First Letter of St. Paul to the Corinthians 10:16-17

"Mend your ways, encourage one another, live in harmony,
and the God of love and peace will be with you all.
Second Letter of Paul to the Corinthians 13:11

"Only conduct yourselves in a way worthy of the gospel of Christ, so that, whether I come and see you or am absent, I may hear news of you, that you are standing firm in one spirit, with one mind struggling together for the faith of the gospel."
Letter of St. Paul to the Philippians 1:27


1 The Navarre Revised Standard Version of the Holy Bible. Four Courts Press, Dublin, Ireland, 1999-2005.
2 The Writings of Christopher Dawson, in Gerald Russello (ed): Christianity and European Culture (Washington DC: Catholic University of America Press, 1998), 34-45, 84-97, 170-181.
3 Bishop Timothy Ware. "The Reunion of Christians," in The Orthodox Church, Second Edition. (London: Penguin, 1997), 307-327.
4 Thomas Bokenkotter. Concise History of the Catholic Church. Image Books, Doubleday, New York, 2004.
5 Pope John XXIII. Announcement of Second Vatican Council, January 25, 1959. Vatican II Council Daybook, Volume 1, Session 1, October 11 - December 8, 1962. National Catholic Welfare Conference, Washington, D. C., 1-2, 1965.
6 Pope John XXIII. Opening Speech of Second Vatican Council, October 11, 1962. Vatican II Council Daybook, Volume 1, Session 1, National Catholic Welfare Conference, Washington, D. C., 25-29, 1965.
7 Hans Urs von Balthasar. Razing the Bastions, 1952. (San Francisco: Ignatius Press, 1993), 10.
8 Alan Schreck. The Teachings of Vatican II. Class Lectures and Texts, Franciscan University, Steubenville, Ohio, 2004.
9 Douglas Bushman (ed), The Sixteen Documents of Vatican II. Pauline Books and Media, Boston, 1999.
10 Avery Cardinal Dulles. Models of the Church, Expanded Edition (New York: Image Classics, 2002), 114-129.
11 Ratzinger JC and Messori V. The Ratzinger Report. (San Francisco: Ignatius Press, 1986), 46-48, 155-166.
12 Alan Schreck. The Catholic Challenge. (Ann Arbor, Michigan: Servant Publications, 1991), 177-214.
13 David M. McCarthy. The Heart of Catholic Social Teaching. (Grand Rapids, Michigan: Brazos Press, 2009), 55-67.
14 William J. Byron SJ. "Ten Building Blocks of Catholic Social Teaching," America Vol. 179, 13:9-12, October 31, 1998.
15 Compendium on the Social Doctrine of the Church. Rome: Libreria Editrice Vaticana, 2004.
16 John T. Noonan Jr. The Lustre of Our Country: The American Experience of Religious Freedom. (Berkeley: University of California Press, 1998), 331-353.
17 Decree on Ecumenism. The Documents of Vatican II. Austin Flannery (ed) Dublin, Ireland: Dominican Publications, 1998.
18 Pope John Paul II. Crossing the Threshold of Hope. (New York: AA Knopf, 1994), 159-162.
19 Catechism of the Catholic Church, Second Edition. Libreria Editrice Vaticana (Washington, DC: US Catholic Conference, 2000), Articles 1396-1400.
20 Pope John Paul II. That All May Be One, the encyclical Ut Unum Sint. Pauline Books & Media, Boston, March 25, 1995.
21 Pope John Paul II. The Apostolic Letter Tertio Millennio Adveniente, Articles 33-34. Pauline Books & Media, Boston, November 10, 1994.