Today’s Catechism sections discuss the unity of the Catholic Church. Supporting material comes from the Decree on Ecumenism, “Unitatis Redintegratio”.

Paragraph 3. THE CHURCH IS ONE, HOLY, CATHOLIC, AND APOSTOLIC

811 "This is the sole Church of Christ, which in the Creed we profess to be one, holy, catholic and apostolic."256 These four characteristics, inseparably linked with each other,257 indicate essential features of the Church and her mission. The Church does not possess them of herself; it is Christ who, through the Holy Spirit, makes his Church one, holy, catholic, and apostolic, and it is he who calls her to realize each of these qualities.

812 Only faith can recognize that the Church possesses these properties from her divine source. But their historical manifestations are signs that also speak clearly to human reason. As the First Vatican Council noted, the "Church herself, with her marvellous propagation, eminent holiness, and inexhaustible fruitfulness in everything good, her catholic unity and invincible stability, is a great and perpetual motive of credibility and an irrefutable witness of her divine mission."258

I. THE CHURCH IS ONE

"The sacred mystery of the Church's unity" (UR 2)

813 The Church is one because of her source: "the highest exemplar and source of this mystery is the unity, in the Trinity of Persons, of one God, the Father and the Son in the Holy Spirit."259 The Church is one because of her founder: for "the Word made flesh, the prince of peace, reconciled all men to God by the cross, . . . restoring the unity of all in one people and one body."260 The Church is one because of her "soul": "It is the Holy Spirit, dwelling in those who believe and pervading and ruling over the entire Church, who brings about that wonderful communion of the faithful and joins them together so intimately in Christ that he is the principle of the Church's unity."261 Unity is of the essence of the Church:

What an astonishing mystery! There is one Father of the universe, one Logos of the universe, and also one Holy Spirit, everywhere one and the same; there is also one virgin become mother, and I should like to call her "Church."262

814 From the beginning, this one Church has been marked by a great diversity which comes from both the variety of God's gifts and the diversity of those who receive them. Within the unity of the People of God, a multiplicity of peoples and cultures is gathered together. Among the Church's members, there are different gifts, offices, conditions, and ways of life. "Holding a rightful place in the communion of the Church there are also particular Churches that retain their own traditions."263 The great richness of such diversity is not opposed to the Church's unity. Yet sin and the burden of its consequences constantly threaten the gift of unity. And so the Apostle has to exhort Christians to "maintain the unity of the Spirit in the bond of peace."264

815 What are these bonds of unity? Above all, charity "binds everything together in perfect harmony."265 But the unity of the pilgrim Church is also assured by visible bonds of communion:
- profession of one faith received from the Apostles;
-common celebration of divine worship, especially of the sacraments;
- apostolic succession through the sacrament of Holy Orders, maintaining the fraternal concord of God's family.266

816 "The sole Church of Christ [is that] which our Savior, after his Resurrection, entrusted to Peter's pastoral care, commissioning him and the other apostles to extend and rule it.... This Church, constituted and organized as a society in the present world, subsists in (subsistit in) the Catholic Church, which is governed by the successor of Peter and by the bishops in communion with him."267

The Second Vatican Council's Decree on Ecumenism explains: "For it is through Christ's Catholic Church alone, which is the universal help toward salvation, that the fullness of the means of salvation can be obtained. It was to the apostolic college alone, of which Peter is the head, that we believe that our Lord entrusted all the blessings of the New Covenant, in order to establish on earth the one Body of Christ into which all those should be fully incorporated who belong in any way to the People of God."268

IN BRIEF

866 The Church is one: she acknowledges one Lord, confesses one faith, is born of one Baptism, forms only one Body, is given life by the one Spirit, for the sake of one hope (cf ⇒ Eph 4:3-5), at whose fulfillment all divisions will be overcome.

The Decree on Ecumenism, “Unitatis Redintegratio” (2) discusses the unity of the Church:

2. What has revealed the love of God among us is that the Father has sent into the world His only-begotten Son, so that, being made man, He might by His redemption give new life to the entire human race and unify it.(2) Before offering Himself up as a spotless victim upon the altar, Christ prayed to His Father for all who believe in Him: "that they all may be one; even as thou, Father, art in me, and I in thee, that they also may be one in us, so that the world may believe that thou has sent me".(3) In His Church He instituted the wonderful sacrament of the Eucharist by which the unity of His Church is both signified and made a reality. He gave His followers a new commandment to love one another,(4) and promised the Spirit, their Advocate,(5) who, as Lord and life-giver, should remain with them forever.

After being lifted up on the cross and glorified, the Lord Jesus poured forth His Spirit as He had promised, and through the Spirit He has called and gathered together the people of the New Covenant, who are the Church, into a unity of faith, hope and charity, as the Apostle teaches us: "There is one body and one Spirit, just as you were called to the one hope of your calling; one Lord, one faith, one Baptism".(6) For "all you who have been baptized into Christ have put on Christ ... for you are all one in Christ Jesus".(7) It is the Holy Spirit, dwelling in those who believe and pervading and ruling over the Church as a whole, who brings about that wonderful communion of the faithful. He brings them into intimate union with Christ, so that He is the principle of the Church's unity. The distribution of graces and offices is His work too,(8) enriching the Church of Jesus Christ with different functions "in order to equip the saints for the work of service, so as to build up the body of Christ".(9)

In order to establish this His holy Church everywhere in the world till the end of time, Christ entrusted to the College of the Twelve the task of teaching, ruling and sanctifying.(10) Among their number He selected Peter, and after his confession of faith determined that on him He would build His Church. Also to Peter He promised the keys of the kingdom of heaven,(11) and after His profession of love, entrusted all His sheep to him to be confirmed in faith(12) and shepherded in perfect unity.(13) Christ Jesus Himself was forever to remain the chief cornerstone(14) and shepherd of our souls.(15)

Jesus Christ, then, willed that the apostles and their successors - the bishops with Peter's successor at their head - should preach the Gospel faithfully, administer the sacraments, and rule the Church in love. It is thus, under the action of the Holy Spirit, that Christ wills His people to increase, and He perfects His people's fellowship in unity: in their confessing the one faith, celebrating divine worship in common, and keeping the fraternal harmony of the family of God.

The Church, then, is God's only flock; it is like a standard lifted high for the nations to see it:(16) for it serves all mankind through the Gospel of peace(17) as it makes its pilgrim way in hope toward the goal of the fatherland above.(18)

This is the sacred mystery of the unity of the Church, in Christ and through Christ, the Holy Spirit energizing its various functions. It is a mystery that finds its highest exemplar and source in the unity of the Persons of the Trinity: the Father and the Son in the Holy Spirit, one God.

Footnotes

256 LG 8.
257 Cf. DS 2888.
258 Vatican Council I, DS Filius 3: DS 3013.
259 UR 2 # 5.
260 GS 78 # 3.
261 UR 2 # 2.
262 St. Clement of Alexandria, Paed. 1, 6, 42: PG 8,300.
263 LG 13 # 2.
264 ⇒ Eph 4:3.
265 ⇒ Col 3:14.
266 Cf. UR 2; LG 14; ⇒ CIC, can. 205.
267 LG 8 # 2.
268 UR 3 # 5.