From the Christian perspective, prayer is the only adequate response to God’s indiscriminate call to the human heart. Yet, prayer’s importance notwithstanding, many Christians practice their faith without an understanding of the distinctively Trinitarian nature of Christian prayer. In the twentieth century, Karl Rahner observed as both a theologian and pastor that many Christians, in praxis if not in theory, were unaware of the implications that follow from the uniquely Christian confession of the Trinity:
Despite their orthodox confession of the Trinity, Christians are, in their practical life, almost mere “monotheists.” We must be willing to admit that, should the doctrine of the Trinity have to be dropped as false, the major part of religious literature could well remain virtually unchanged.
Rahner blames the manualist theology of his day for the inattention to the relevance of Trinitarian doctrine, a negligence that has starved not only speculative theology but also the layperson’s notion of prayer. Is it any wonder, “when theology considers it almost a matter of course that the ‘Our Father’ is addressed in the same way. . . to the three divine persons,” that the average Christian imagines herself as flinging prayers to God from the outside, as any other monotheist would hope to do? The criticism here is, of course, not that Christians are monotheists but that they are at times—albeit unwittingly—Modalists, the early Christian heresy that reduced Father, Son, and Spirit to three “masks” or “ways” (modi) by which a singular divinity manifests itself. By consciously integrating our understanding of prayer with the uniquely Christian form of monotheism—the worship of three divine persons untied in a numerically singular nature—we can and should attend to our place within the Trinity’s inner-life, a divine reality into which Christians have been baptized.
One way to correct the Modalistic tendency that affects our idea of prayer, and thereby awaken ourselves to a sense of God’s triune-ness, is to confront the difficult words of Origen of Alexandria on the “Our Father.” He writes:
Now if we are to take prayer in its most exact sense, perhaps we should not pray to anyone begotten, not even to Christ Himself, but only to the God and Father of all, to whom even our Savior Himself prayed, as we have explained, and to whom He taught us to pray. For when He heard “teach us to pray,” He did not teach us to pray to Himself but to the Father by saying “Our Father in heaven, and so forth” (Lk. 11:1ff.; Mt. 6:5ff.) . . . Consequently, . . . we should pray only to the God and Father of all, yet not without the High Priest, who was appointed “with an oath” according to the verse, “He has sworn and will not change His mind, You are a priest forever after the order of Melchisedek” (Ps. 110:4; Heb. 7:20–21).
This passage is certainly challenging, and today we undoubtedly benefit from a fuller articulation of Christ’s consubstantial divinity than what was available to Origen. We can avoid a superficial reading of this passage by recognizing that Origen himself expresses passionate devotion to the Son elsewhere in his writings, such as in his Commentary on the Song of Songs. Thus, I do not think that Origen would dispute the importance of directly addressing Christ or the Holy Spirit in our prayers. Different people will find that at some moments of their lives they find it best to pray to Christ, who has experienced human tragedy, whereas at other times they especially desire the guidance of the Spirit in their speech or decision-making.
It is perfectly appropriate to address either the Son or the Spirit in our prayers. Origen’s central contention lies elsewhere; to discern this, we must carefully attend to two important distinctions that he makes. First, he notes that prayer, “in its most exact sense,” is ultimately oriented to God the Father; I suggest that Origen here intends to describe the objective structure of Christian prayer itself and not necessarily the intentions of the praying subject, which may take the form of prayers to the Spirit or Son such as Veni Sancte Spiritus and Agnus Dei. In other words, our prayers are ultimately directed to the Father regardless of whether or not we are intentionally speaking to the Father, Son, or Spirit.
Of course, we ought not confuse this insight with Origen’s unambiguous claim that the “Our Father” is not a plea to the divine nature in general, nor to each Trinitarian person univocally, but is instead a direct address to the Father. In this instance of explicit prayer to the Father, we uncover our inability to address God the Father with familial immediacy unless we are in some sense truly sons and daughters. Thus, the second distinction that Origen makes is that direct prayer to the Father is impossible unless it is carried out through the Son (1 Tim 2:5). As Origen clarifies,
And if it is true that one who is scrupulous about prayer ought not to pray to someone else who prays, but rather to the Father whom our Lord Jesus taught us to address in prayers, it is especially true that no prayer should be addressed to the Father without Him [Jesus], who clearly points this out Himself when He says, “Truly, truly, I say to you, if you ask anything of the Father, He will give it to you in my name. Hitherto you have asked nothing in my name; ask, and you will receive, that your joy may be full” (Jn. 16:23–24). Now He did not say “ask me” or simply “ask the Father.” On the contrary, He said “If you ask anything to the Father, He will give it to you in my name.” For until Jesus taught this, no one asked the Father in the name of the Son.
Origen highlights that Christians can only approach the Father as his children because they are united to Jesus Christ and, by participating in his divine sonship, can appropriate his filial prayer as their own. As we read in John’s gospel: “But to all who received him [the Word], who believed in his name, he gave power to become children of God” (Jn 1:12). For this reason, the Son is no less essential to prayer even though the Christian has a different relationship to the Son than he does to the Father. Along similar lines, St. Augustine articulates Christ’s multifaceted role in Christian prayer: “The Son] prays for us as our priest, prays in us as our Head, and is prayed to by us as our God. Therefore let us acknowledge our voice in him and his in us.”
Origen’s words in the above passage accord not only with Augustine but also with the tendency of the New Testament to relate human salvation to each of the Trinitarian persons in different respects rather than to the divine nature in general. We see this especially in Paul’s theology of adoption by God, which in his epistles almost always refers specifically to God the Father:
For you did not receive the spirit of slavery to fall back into fear, but you have received the spirit of sonship. When we cry, “Abba! Father!” it is the Spirit himself bearing witness with our spirit that we are children of God, and if children, then heirs, heirs of God and fellow heirs with Christ (Rom 8:15-17; emphasis added).
The Christian can pray to the Father only because he prays through the Son in the union brought about by the Holy Spirit. According to Cipriano Vagaggini, we often find in both the New Testament and the early liturgy of the Church the formula a, per, in, ad to describe the distinctive relationships of the Father, Son, and Spirit to the salvation of humans. Vagaggini writes,
This scheme, expressed sometimes in its entirety, sometimes only in part while the rest is implied, is formulated as follows: every good thing comes to us from [Latin: a] the Father, through [per] the mediation of His incarnate Son, Jesus Christ, by means of the presence in [Latin: in] us of the Holy Spirit; and likewise, it is by means of the presence of the Holy Spirit, through the mediation of the incarnate Son, Jesus Christ, that everything returns to [ad] the Father.
The movements a, per, in, ad in the economy of salvation reveal the rhythm of the immanent Trinity and therefore also the rhythm of our prayer as adopted children among the Father, Son, and Spirit.
In the works of many early Church fathers, such as Athanasius’s Letters to Serapion on the Holy Spirit, a variant of the aforementioned formula is used to describe the Christian’s distinct relationships to each trinitarian person upon baptism, in which he or she is immersed into the Trinity’s inner-life: “For there is one grace from (ἐκ) the Father which is perfected through (δι’/διά) the Son in (ἐν) the Holy Spirit.” Following the subordinationist threat of Arianism, however, the Church shifted its emphasis toward the unity of the Godhead. Yet, now that Arianism and its children have been laid to rest, we must reclaim our awareness of the Christian’s distinct relations to the Trinitarian persons, especially in prayer, while at no point surrendering the Godhead’s numerical unity and thereby falling into tritheism.
One can expect resistance toward a retrieval of prayer’s intra-Trinitarian dimension stems from a narrow, one-sided reading of Thomas Aquinas and his teaching on “appropriation.” In order to safeguard the unity of God’s nature and activity, it has traditionally been asserted that all of God’s actions ad extra, toward creation, are shared by all of the members of the Trinity; at the same time, certain actions or qualities are still “appropriated” to specific persons of the Trinity due to an analogous likeness to their distinct relationship within the immanent Trinity. For instance, we refer to the Father as “Creator,” even though the Son and Spirit are also involved in creation, since the Father’s relation to the Son and Spirit as source and origin is particularly analogous to being the source of creation’s existence.
Aquinas not only applies this principle to creation and the like but also to salvation history, such as God’s adoption of Christians: “Now although, in God, to beget belongs to the Person of the Father, yet to produce any effect in creatures is common to the whole Trinity, by reason of the oneness of their Nature . . . Therefore it belongs to the Trinity as a whole to adopt men as sons of God.” He then goes on to note the different appropriations in this case: “Therefore adoption, though common to the whole Trinity, is appropriated to the Father as its author; to the Son as its exemplar; to the Holy Ghost, as imprinting on us the likeness of this exemplar.”
Yet, a reductionistic interpretation of appropriation, which Rahner refers to as “mere appropriation,” threatens to disregard as almost metaphorical any distinct relationships among the Trinitarian persons to humans within salvation history. Rahner counters this view by noting that in the Incarnation we have a clear instance where “mere” appropriation does not apply; the Father and Son are involved in the Incarnation, but the divine person of the Son alone has a hypostatic relation to a human nature and therefore a unique relationship to creation that is not shared by the Father and Son.
Rather than being an exception to the rule, the Incarnation is precisely the lens from which we must view our theology, especially with respect to God’s relationship to mankind. Rahner argues that those who argue for “mere appropriation” neglect that the common ad extra activity of the Trinity is still “possessed by each of the three persons in his own proper way.” Moreover, he suggests that appropriation “is absolutely valid only where the ‘supreme efficient cause’ is concerned (DS 3814)” and does not exclude the distinctive relationship of “quasi-formal” causality possible between the Christian and a person of the Trinity, such as Christians being conformed into the image of Christ (Rom 8:29; 2 Cor 3:18).
Thus, while retaining a certain doctrine of appropriation, we should consider an interpretation of it that does not exclude the Christian’s differing relationships among the Father, Son, and Spirit rather than necessitating a singular, non-Triune relationship to the divine nature. Recognizing that, for instance, the Christian’s filial relationship to the Father is different than his or her relationship to the Son is especially imperative if we are to account for the patristic insight, as in Athanasius’s theology, that Christians are at baptism immersed into the Trinity’s inner-life. Luis Ladaria argues that a rapprochement is possible between the traditional teaching of appropriation and the insistence of distinction among the Trinitarian persons: “The principle according to which all divine action toward the world is common to the whole Trinity should not cause us to forget that this Trinity which is absolutely one in principle, is in turn a principle which contains difference within itself. Since the saving activity must reflect in some way the very being of God, the relations with each of the divine persons proper to the Christian perfectly fit here.”
Ladaria goes on to suggest,“This differentiated activity of the persons is a reflection of the intra-divine distinction.” I would go a step further and propose that it is precisely because Christians share in the mutual relations of the immanent Trinity—the only way in which the Trinitarian persons differ—that appropriation is, in this instance, unnecessary to safeguard divine unity. Concretely, we may understand this as follows: the Father has a unique paternal relationship to the Christian who has been conformed to the image of the divine Son and who has thereby appropriated the Son’s distinct filial relationship as begotten by the Father; the Son’s relationship to the Father remains unchanged even though it is “opened” up for humans to participate.
While we may find ourselves too distracted in prayer to pay attention to one divine person, let alone all three, we nonetheless live out the Christian journey immersed within the Triune God’s inner life. Every moment of Christian prayer takes place at the side of Christ, whose cry for “Abba, Father” becomes our own. The Spirit holds us fast to the divine Son, so that even as we carry out quotidian duties, most of the time oblivious to the sacred mystery we inhabit, we still keep one foot in the divine dance of mutual indwelling, perichoresis.
But we do not live out the trinitarian mystery alone, for the Holy Spirit has joined us to Christ who is the Head and Bridegroom of a Church, that is, innumerable others with whom we have been elevated into a share of God’s inner life. Our individual prayers are no replacement for, but are rather oriented to, the liturgical prayer of the Church, especially the Eucharistic prayer— which, we should note, is always addressed to the Father.
As Hans Urs von Balthasar put it: “There is an unshakeable bond between the Church’s great, secure prayer and the tentative stumbling prayer of the individual. In the world there are millions who pray, but all their prayers are gathered up into the one, all-embracing prayer of the Church, the Bride.” God willing, we can make fully our own the prayer of Christ’s Bride and thereby enjoy into eternal life the unveiled vision, from within, of that “Love that moves the sun and the other stars.”
 Karl Rahner, The Trinity (New York: Crossroad, 2018), 10-11.
 Ibid., 12.
 One can dispel the aura of trinitarian unorthodoxy that clouds the popular caricature of Origen by recalling that Origen (d. 254) wrote long before the subtle definitions of Nicaea (325) and Constantinople (381).
 Origen, On Prayer, XV.1-2 in Origen: Selected Writings (Mahwah, NJ: Paulist, 1979) 81—170; emphasis added.
 Ibid.; emphasis added.
 St. Augustine, En. in Ps. 85,1:PL 37,108.
 Cyprian Vagaggini, O.S.B., Theological Dimensions of the Liturgy: A General Treatise on the Theology of the Liturgy (Collegeville, MN: Liturgical, 1976), 198. Vagaggini provides the following scriptural examples, which certainly differ in the extent to which the formula is explicitly present: Eph 1:3-14; 2:4-5; 18-20; Rom 8:3-17; 15:15-19; Gal 4:4-6, 1 Cor 6:19-20; 12:4-6; 2 Cor 1:21-22; 13:13; Acts 2:32-33; 5:30-32; 15:7-11.
 Athanasius, “Letters to Serapion on the Holy Spirit” in Works on the Spirit: Athanasius and Didymus (Yonkers, NY: St Vladimir’s Seminary, 2011), 1.14.6; emphasis added.
 Luis F. Ladaria, The Living and True God: The Mystery of the Trinity (Miami, FL: Convivium, 2010), 307.
 Thomas Aquinas, Summa Theologiae, III, q. 23, a. 2, co; In the Sed Contra of this article, Aquinas also writes, “But when we say to God ‘Our Father,’ we address the whole Trinity: as in the case with the other names that are said of God in respect of creatures.” Rather than contradicting what we have been arguing here, it seems that Aquinas is extending the name of the Father to the entire Trinity in the sense that the Trinity acts as one to create and in this sense is analogously “Father” to creation. Because Aquinas interprets Father in a different sense than Origen, i.e. not as exclusively referring to the first person of the Trinity, he does not simply outright conflict with Origen’s insistence that the Our Father is addressed only to God the Father.
 Aquinas, ST, III, q. 23, a. 2, ad. 3.
 Ladaria, op. cit., 52
 Rahner, op. cit., 77.
 Ladaria, op. cit., 308.
 Hans Urs von Balthasar, Prayer, (San Francisco, CA: Ignatius, 1986), 70.
 Ladaria, op. cit., 36.
 Von Balthasar, op. cit., 100.
 Dante Alighieri, Paradiso, 33.