The “communion of saints” is a definitive mark of the Christian imagination conformed to the mystery of salvation: the communion of holy persons invites and demands an act of faith for Christian belief to build toward completion. In fact, it is the exercise of fidelity to the promises of Christ in the face of death that gave this expression its primary meaning for Western Christianity. This meaning was carried into and is now borne by the Apostles’ Creed, “the most universally accepted creed in Western Christendom.” Every saint has a history and so does the article of faith that attests to the communion in which they share. The lives of saints arise from the work of God in the world while the article symbolizing their communion arises from the Church’s reflection on the life of faith in the Spirit.
In fact, it was the intensity of faith of particular Christians, in a particular era, in a particular region, that helped the article of communio sanctorum to gain recognition as intrinsic to the faith:
The fourth century witnessed an enormous expansion of the devotion which the Church had paid to its saints and illustrious dead from the earliest times. Even at the beginning of the third century the author of the Passion of Perpetua and Felicitas assured his readers that his purpose in writing out what had happened was to enable them to enjoy communion with the holy martyrs and through them with Jesus Christ . . . It is evident that in the fourth century the consciousness of communion with the redeemed in heaven, who had already tasted of the fullness of the glory of Christ, was as real and as rich in hope to the theologians as to circles of ordinary Christians. Thus, “communion of saints” gave expression to conceptions which were very vividly present to the minds of fourth and fifth century churchmen, particularly in those regions of Western Europe where . . . the Apostles’ Creed was molded into its final shape.
The occasion for the articulation of the “communion of saints” as part of the creed arose from the devotions to the blessed dead that were abundant and thriving in the regions where the Apostles’ Creed developed. In other words, as the faithful exercised the faith into which they were immersed at baptism, they applied this faith to the veneration of first the martyrs and then other holy witnesses. Only after this application of the faith was exercised did it come to be recognized as normative for the faith. Devotion drew out orthodoxy.
In this way, communio sanctorum was first believed implicitly and practiced devotionally—almost instinctively—before it was confessed explicitly and handed down in the creed. Upon reflection, the Church recognized the practice of exercising communion with the saints as intrinsic to the one faith it professed, and thus incorporated this dimension of life in the Spirit into the final section of its baptismal creed. Even today, when the profession of faith is made prior to the rite of baptism in the Catholic Church, the final affirmative responses to the interrogations of faith lead to the celebrant’s announcement that “This is our faith. This is the faith of the Church. We are proud to profess it, in Christ Jesus our Lord.” The communion of saints is an element of that faith which the Church proudly professes.
The Communion of Saints at Vatican II
In the Second Vatican Council’s Dogmatic Constitution on the Church—Lumen gentium—the Church is proclaimed to be composed of a “union of wayfarers with the brothers and sisters who sleep in the peace of Christ” and that “this union is reinforced by an exchange of spiritual goods.” The Church recognizes that “some of [Christ’s] disciples are pilgrims on earth, others have died and are being purified, while still others are in glory.”
Though death separates the wayfarers from those in the glory of heaven and those being purified after death, the council acknowledges that the faith it inherits and now professes entails belief in a “living communion” between the living and the (blessed) dead—that is, the council espouses belief in an interchange between different spheres of existence. It teaches “that the authentic cult of the saints [consists] . . . in a more intense practice of our love.” The practice of love unfolds as the living communicate with the saints through giving thanks to God for them, accepting their ancestors’ faith as their own, asking for their help through prayer, remembering their lives and witness, and joining them in the praise of God in the liturgy.
Although it does not use the phrase “communion of saints” in this document, the council does describe and vouch for the practice of communion, which, as the council attests, has always been a part of the faith. As though it were intentionally giving a defense of the development of orthodox teaching from its implicit reality to explicit declaration, the council announces that:
The church has always believed that the apostles and Christ’s martyrs, who gave the supreme witness of faith and charity by the shedding of their blood, are closely united with us in Christ; it has always venerated them, together with the Blessed Virgin Mary and the holy angels, with a special love, and has asked piously for the help of their intercession. Soon there were added to these others who had chosen to imitate more closely the virginity and poverty of Christ, and still others whom the outstanding practice of the Christian virtues and the wonderful grace of God recommended to the pious devotion and imitation of the faithful.
The practice that began in the first few centuries of the Church of venerating the blessed dead and exercising communion with them—a practice that was formally recognized as proper to the faith itself in conformity with belief in the Holy Spirit who unites the living and the dead through the merits of Christ—is here proclaimed as original to the Christian faith from its inception.
Through the council, the Church speaks with authority regarding the truth and importance of this union that “is in no way interrupted” between the living and the dead who share in the love of Christ. Whereas once this union existed in the practices of the faithful who clung to the promises of Christ without an explicit doctrine to define this dimension of faith, in the present age the doctrine is clearly established not only as an article recited in the baptismal creed, but also through the authoritative teaching of an ecumenical council. While now that which was once absent—the doctrine—is clearly present, the question becomes whether that which was once present—the practice—remains so. Is that which is confessed explicitly supported in the practice of faith of the modern Christian?
The Problem of Venerating the Saints
In an essay dealing with this very chapter of Lumen gentium, Karl Rahner indicates that the Constitution is attentive to the teaching of the Church but not to the practice of the faithful regarding this teaching:
By these statements—this is the message of the decree whether explicitly or implicitly expressed—the situation is made clear. We can and should venerate the saints. The only thing left for us to do is to respond with the reality with which we have been presented in the appropriate manner, and in fact to venerate the saints. At this point, however, it may appear to the man of our own times that one factor of decisive importance has been overlooked, namely himself. In other words the question has not been answered as to why and how he, in view of his own special peculiarities, can achieve any kind of relationship with the world of the saints even though the objective reality of this world is not denied.
According to Rahner’s assessment, the “man of our own times” does not find in this teaching of the Church the means, the motivation, or the grist for the imagination that will lead him, in his unique particularity, into a lived relationship with the blessed dead. Even when the Christian joins in the Church’s liturgy and, partaking in the sacraments, shares in the “spiritual goods” or “holy things” of the Church’s communion, he does not easily conceive of himself as participating in a communion with the saints per se.
Unmistakably, the council confirms the objective fact of a communion that binds together the Church’s pilgrims with those in the glory of heaven and those in the state of purification. In Rahner’s view, however, it does not answer the twin questions of why and how the modern person actually venerates the saints. These questions point to an even more fundamental twofold question: why and how do we believe in the communion of saints? Even though this belief has been exercised throughout the centuries within the Church and, by at least the middle of the ninth century, was explicitly articulated as an article of faith, what has yet to be satisfactorily accomplished is a systematic theological account of why and how this belief is intrinsic to the Christian faith as such (this is the task of my book, Work of Love, from which this excerpt comes). This theological account is neither the source of the practice of faith nor a necessary prerequisite for an articulation of faith; rather, the theological account helps tie together the practice and the articulation so that when the former is flagging—as Rahner suggests it is in the modern age—the theology can explicate what is professed, thereby revealing once again what has always been proclaimed. Theology, in this case, assists doctrine in directing the very practice that gave rise to the doctrine in the first place. 
Rather than dealing with either distinct individuals or an abstract communion, veneration of the saints is concerned with relating to particular persons bonded together in communion. The communion in which the faithful profess belief as communio sanctorum is a communion of holy persons who, according to Lumen Gentium, are united to both the Church’s pilgrims and those undergoing purification after death. What is as-yet theologically underdetermined is how that which makes these particular persons holy is precisely that which forms them into one communion. In other words, what unites them as a communion and what makes them holy is one and the same: the love of Christ that becomes their own way of loving. The unique particularities of these holy persons were, each in their own way, conformed to and transformed by the love of God in Christ. At the same time, though, this transformation that brought them into the union of one body, for holiness, which is the graced sharing of divine life, is impossible in isolation. Holiness entails communion, for holiness is given in the Spirit, who is the communion of the Father and the Son given over to the world. As an article of the Christian faith, communio sanctorum at once indicates the unsubstitutable particularity of holy persons, their communion in Christ through the Spirit, and the bonds that unite them. In Eastern Christianity, it is on the bonds—especially the sacraments—that the primary emphasis of the “communion of saints” has traditionally been placed. In the West, however, the most universal of all the Christian creeds—the Apostles’ Creed—presents the article as that which arose from the veneration of holy persons. It is this practice that the Church says the faithful can and should continue today.
The Fullness of the Christian Faith
Communing with the saints is not an arbitrary recommendation; rather, it is essential to professing and practicing the Christian faith in its fullness. For when the Church announces its saints, it proclaims the permanent validity of the humanity of Christ and the real, historical efficacy of the Incarnation. On this point, Rahner seeks to make the connection between the pronouncement of sainthood and the mystery at the heart of the Church:
When the Church declares someone to be a Saint, this is much more a necessary part of the Church’s realization of her own being…she must be able to state her holiness in the concrete. She must have a “cloud of witnesses” whom she can indicate by name. She cannot merely maintain that there is a history of salvation (without it being known exactly where it takes place with real, final success), but she must really relate that very eschatological history of salvation which she is herself. The prize of her actual Saints belongs to her innermost being and is not merely something which she “also” achieves “on the side,” something which has been inspired by a purely human need for hero worship.
In Rahner’s estimation, this is important because the heart of the Christian faith is the Incarnation of the Word of God, who was not merely “at one time of decisive importance for our salvation . . . he is now and for all eternity the permanent openness of our finite being to the living God of infinite, eternal life.” The union of divine and human natures in the one person of Jesus of Nazareth is the once for all event of salvation that, through the Spirit, is a mystery contemporaneous with all of history.
In recognizing the holiness of its own members, the Church confesses the truth of the Incarnation: that the humanity of Christ was neither temporary nor simply apparent. The humanity of Christ was and is real; it was and is the same humanity that the members of the Church possess. To see the holiness of its own members, the Church sees the merits of the life, death, and Resurrection of the Incarnate Word in human history. The third section of the creed contains the statements of belief that pertain to the Holy Spirit, who makes present the saving mysteries of Christ (recited in the second part of the creed) and thereby opens creation to participation in divine life. The Church’s saints are both beneficiaries and heralds of this work of sanctification. Their communion with one another and eschatologically with the whole Church is guaranteed in the person of the Holy Spirit.
The status of communio sanctorum is at once a Christological and a pneumatological matter. It is Christological in that it concerns the full reach of the Incarnation to humanity—and indeed creation—as such, and it is a pneumatological matter since it arises from the activity of the Holy Spirit to communicate the merits of the incarnation to the world. Veneration of the saints is an act of fidelity to the promises of Christ through the sanctifying work of the Holy Spirit. The saints are icons of God’s Triunity, for they receive the eternal love of God the Father in their conformity to the mysteries of Jesus Christ, the only begotten Son, as they share in the communion of the Holy Spirit.
The problem of the why and how of the modern Christian’s veneration of the saints—and, furthermore, the why and how of belief in communio sanctorum—is thus an issue that bears directly on belief in the Incarnation. The most complete account of the mystery of the Incarnation will be the one that sees also the effects of the incarnation on real, historical human beings as part of the eternal mystery of the person of Christ. This account will not only bear upon professions of faith, but also upon practices of faith. The theologian’s role is therefore to assist in the illumination of the full mystery of the incarnation, which, in this instance, means explicating why and how the communio sanctorum is inextricably enfolded within Christ’s person, who is identical with his salvific work.
EDITORIAL NOTE: This excerpt comes from Work of Love: A Theological Reconstruction of the Communion of Saints. It is part of an ongoing collaboration with the University of Notre Dame Press. You can read our excerpts from this collaboration here. All rights reserved.
 Jaroslav Pelikan, Credo: Historical and Theological Guide to Creeds and Confessions of Faith in the Christian Tradition (New Haven, Conn.: Yale University Press, 2005), 187.
 Ibid., 396–97.
 Austin Flannery, ed., “Lumen Gentium: Dogmatic Constitution on the Church,” in Vatican Council II: Constitutions, Decrees, Declarations, rev. ed. (Northport, N.Y.: Costello, 1996), §49.
 Flannery, §48.
 Flannery, §51.
 Flannery, §51.
 Flannery, §50.
 Flannery, §50 (emphases added).
 Flannery, §49.
 Karl Rahner, “Why and How Can We Venerate the Saints?” in Theological Investigations, trans. Cornelius Ernst et al., vol. 8 (Limerick, Ireland: Mary Immaculate College, 2000), 4.
 See Jaroslav Pelikan, Credo: Historical and Theological Guide to Creeds and Confessions of Faith in the Christian Tradition (New Haven, Connecticut: Yale University Press, 2005), 75.
 J. N. D. Kelly, Early Christian Creeds (New York: Longman, 1972), 389–90; Susan Wood, “Sanctam Ecclesiam Catholicam, Sanctorum Communionem,” in Exploring and Proclaiming the Apostles’ Creed, ed. Roger Van Harn (Grand Rapids, Michigan: Wm. B. Eerdmans Publishing, 2004), 228; Berard Marthaler, The Creed: The Apostolic Faith in Contemporary Theology, 3rd Revised (New London, Connecticut: Twenty-Third Publications, 2007), 330; Nicholas Ayo, The Creed As Symbol (Notre Dame, Indiana: University of Notre Dame Press, 1990), 133.
 Kelly, Early Christian Creeds, 394; see also Francis John Badcock, The History of the Creeds (New York: The Macmillan Company, 1938), 243–272, especially 271; Emilien Lamirande, “The History of a Formula,” in The Communion of Saints, trans. A. Manson (New York: Hawthorn Books, 1963), 15–38; and Heinz Kruse, “Gemeinschaft Der Heiligen: Herkunft Und Bedeutung Des Glaubensartikels,” Vigiliae Christianae 47, no. 3 (1993): 246–59.
 Karl Rahner, “The Church of the Saints,” in Theological Investigations, trans. Cornelius Ernst et al., vol. 3 (Limerick, Ireland: Mary Immaculate College, 2000), 93, 96 (emphasis in original text); see also Lawrence Cunningham, The Meaning of Saints (San Francisco: Harper & Row, 1980), 32. Michael Plekon, Hidden Holiness (Notre Dame, Indiana: University of Notre Dame Press, 2009); and Michael Plekon, Saints As They Really Are: Voices of Holiness in Our Time (Notre Dame, Indiana: University of Notre Dame Press, 2012).
 Karl Rahner, “The Eternal Significance of the Humanity of Jesus for Our Relationship with God,” in Theological Investigations, trans. Cornelius Ernst et al., vol. 3 (Limerick, Ireland: Mary Immaculate College, 2000), 44 (emphases in original text).
 See Karl Rahner, “All Saints,” in Theological Investigations, trans. Cornelius Ernst et al., vol. 8 (Limerick, Ireland: Mary Immaculate College, 2000), 27.
 see Flannery, §48.
 see Flannery, §50.
 Rahner, “The Eternal Significance of the Humanity of Jesus for Our Relationship with God,” 45.