Dominus Iesus §16

IV. UNICITY AND UNITY OF THE CHURCH

16. The Lord Jesus, the only Saviour, did not only establish a simple community of disciples, but constituted the Church as a salvific mystery: he himself is in the Church and the Church is in him (cf. Jn 15:1ff.; Gal 3:28; Eph 4:15-16; Acts 9:5). Therefore, the fullness of Christ's salvific mystery belongs also to the Church, inseparably united to her Lord. Indeed, Jesus Christ continues his presence and his work of salvation in the Church and by means of the Church (cf. Col 1:24-27),⁴⁷ which is his body (cf. 1 Cor 12:12-13, 27; Col 1:18).⁴⁸ And thus, just as the head and members of a living body, though not identical, are inseparable, so too Christ and the Church can neither be confused nor separated, and constitute a single “whole Christ”‌.⁴⁹ This same inseparability is also expressed in the New Testament by the analogy of the Church as the Bride of Christ (cf. 2 Cor 11:2; Eph 5:25-29; Rev 21:2,9).⁵⁰

Therefore, in connection with the unicity and universality of the salvific mediation of Jesus Christ, the unicity of the Church founded by him must be firmly believed as a truth of Catholic faith. Just as there is one Christ, so there exists a single body of Christ, a single Bride of Christ: “a single Catholic and apostolic Church”‌.⁵¹ Furthermore, the promises of the Lord that he would not abandon his Church (cf. Mt 16:18; 28:20) and that he would guide her by his Spirit (cf. Jn 16:13) mean, according to Catholic faith, that the unicity and the unity of the Church - like everything that belongs to the Church's integrity - will never be lacking.⁵²

The Catholic faithful are required to profess that there is an historical continuity - rooted in the apostolic succession⁵³ - between the Church founded by Christ and the Catholic Church: “This is the single Church of Christ... which our Saviour, after his resurrection, entrusted to Peter's pastoral care (cf. Jn 21:17), commissioning him and the other Apostles to extend and rule her (cf. Mt 28:18ff.), erected for all ages as 'the pillar and mainstay of the truth' (1 Tim 3:15). This Church, constituted and organized as a society in the present world, subsists in [subsistit in] the Catholic Church, governed by the Successor of Peter and by the Bishops in communion with him”‌.⁵⁴ With the expression subsistit in, the Second Vatican Council sought to harmonize two doctrinal statements: on the one hand, that the Church of Christ, despite the divisions which exist among Christians, continues to exist fully only in the Catholic Church, and on the other hand, that “outside of her structure, many elements can be found of sanctification and truth”‌,⁵⁵ that is, in those Churches and ecclesial communities which are not yet in full communion with the Catholic Church.⁵⁶ But with respect to these, it needs to be stated that “they derive their efficacy from the very fullness of grace and truth entrusted to the Catholic Church”‌.⁵⁷

(47) Cf. Second Vatican Council, Dogmatic Constitution Lumen gentium, 14.

(48) Cf. ibid., 7.

(49) Cf. St. Augustine, Enarratio in Psalmos, Ps. 90, Sermo 2,1: CCSL 39, 1266; St. Gregory the Great, Moralia in Iob, Praefatio, 6, 14: PL 75, 525; St. Thomas Aquinas, Summa Theologiae, III, q. 48, a. 2 ad 1.

(50) Cf. Second Vatican Council, Dogmatic Constitution Lumen gentium, 6.

(51) Symbolum maius Ecclesiae Armeniacae: DS 48. Cf. Boniface VIII, Unam sanctam: DS 870-872; Second Vatican Council, Dogmatic Constitution Lumen gentium, 8.

(52) Cf. Second Vatican Council, Decree Unitatis redintegratio, 4; John Paul II, Encyclical Letter Ut unum sint, 11: AAS 87 (1995), 927.

(53) Cf. Second Vatican Council, Dogmatic Constitution Lumen gentium, 20; cf. also St. Irenaeus, Adversus haereses, III, 3, 1-3: SC 211, 20-44; St. Cyprian, Epist. 33, 1: CCSL 3B, 164-165; St. Augustine, Contra adver. legis et prophet., 1, 20, 39: CCSL 49, 70.

(54) Second Vatican Council, Dogmatic Constitution Lumen gentium, 8.

(55) Ibid.; cf. John Paul II, Encyclical Letter Ut unum sint, 13. Cf. also Second Vatican Council, Dogmatic Constitution Lumen gentium, 15 and the Decree Unitatis redintegratio, 3.

(56) The interpretation of those who would derive from the formula subsistit in the thesis that the one Church of Christ could subsist also in non-Catholic Churches and ecclesial communities is therefore contrary to the authentic meaning of Lumen gentium. “The Council instead chose the word subsistit precisely to clarify that there exists only one 'subsistence' of the true Church, while outside her visible structure there only exist elementa Ecclesiae, which - being elements of that same Church - tend and lead toward the Catholic Church”‌ (Congregation for the Doctrine of the Faith, Notification on the Book “Church: Charism and Power”‌ by Father Leonardo Boff: AAS 77 [1985], 756-762).

(57) Second Vatican Council, Decree Unitatis redintegratio, 3.