Here is the second Lenten homily given this year by the preacher of the Pontifical Household, Capuchin Father Raniero Cantalamessa.
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1. Bringing together what unites us
The recent visit of Pope Francis to Turkey, which concluded with his meeting with the Orthodox Patriarch Bartholomew, and in particular the pope’s exhortation to Eastern Christian and Western Christians to share fully their common faith have convinced me of the usefulness of devoting the Lenten meditations for this year to support this desire of the Holy Father, which is also the desire of all Christendom.
This desire for communion is not new. The Second Vatican Council, in Unitatis redintegratio, already urged a special consideration of the Eastern Churches and of their riches (UR 14). St. John Paul II, in his apostolic letter in 1995, Orientale lumen, wrote,
Since, in fact, we believe that the venerable and ancient tradition of the Eastern Churches is an integral part of the heritage of Christ’s Church, the first need for Catholics is to be familiar with that tradition, so as to be nourished by it and to encourage the process of unity in the best way possible for each.
That same holy pontiff formulated a principle that I believe is fundamental for the path to unity: “I pray . . . for fruitful cooperation in the many areas which unite us; these are unquestionably more numerous than those which divide us.” The Orthodox Church and the Catholic Church share the same faith in the Trinity, in the Incarnation of the Word, in Jesus Christ as true God and true man in one single person who died and was raised for our salvation and who has given us the Holy Spirit. We believe that the Church is animated by the Holy Spirit, that the Eucharist is “the source and summit of the Christian life,” that Mary is the Theotokos, the Mother of God, and that eternal life is our destination. What could be more important than this? The differences occur in our manners of understanding and explaining some of these mysteries, so they are secondary and not primary.
In the past, relations between Eastern theology and Latin theology were marked with an obvious apologetic and polemic coloring. They focused—in recent times, fortunately, with more irenic tones—on the distinctions and on what each side believed was different and more correct than the other side. The time has come to reverse this tendency, leaving aside any obsessive insistence on the differences (which are often based on a forced interpretation, if not a distortion, of the other’s thought) and instead to bring together what we have in common and what unites us in one faith. This is necessitated peremptorily by the common duty of proclaiming the faith to a world that has profoundly changed and has different questions and interests than those during the time in which the disagreements arose—a world in which the vast majority no longer understands the meaning of so many of our subtle distinctions and is light- years away from them.
Until now, in the effort to promote unity among Christians, one approach has predominated that could be formulated this way: “First resolve the differences, and then share what we have in common.” The approach that is now increasingly being pursued in ecumenical circles is “Share what we have in common, and then resolve the differences with patience and reciprocal respect.”
The most surprising result of this change in perspective is that the same doctrinal differences, rather than appearing to us as an “error” or a “heresy” of the other side, are beginning to appear more and more often as compatible with one’s own position and at times even as a necessary corrective and an enrichment. We have a concrete example of this, on another front, with the agreement between the Catholic Church and the Lutheran World Federation in 1999 concerning justification by faith.
A wise pagan thinker in the fourth century, Quintus Aurelius Symmachus, noted a truth that acquires its full value if it is applied to the relations among the various theologies of East and West: “Uno itinere non potest perveniri ad tam grande secretum.” (“It is not possible to arrive at such a great a mystery through one path.”) In these meditations we will try to demonstrate not only the necessity but also the beauty and joy of finding ourselves at the summit of a mountain, although we reached it by different slopes, to contemplate the same marvelous panorama of Christian faith.
The great mysteries of faith, whose fundamental agreement in the diversity of the two traditions we will seek to confirm, are the mystery of the Trinity, the person of Christ, the person of the Holy Spirit, and the doctrine of salvation. Two lungs but one breath. That will be the conviction that will guide us on our path of exploration. Pope Francis speaks in this sense of “reconciled differences”: they are not silenced or trivialized but reconciled. Since these are simple Lenten sermons, it is clear that I will touch on very complex problems without any claim to thoroughness, and with an intent that is practical and preliminary rather than speculative.
I approach this task with great humility and almost on tip-toes, knowing how difficult it is to strip oneself of one’s own categories to take on those of others. I am comforted by the fact that the Greek Fathers, along with the Latin Fathers, were for years the daily bread of my studies, and that many later Orthodox authors (Symeon the New Theologian, Nicholas Cabasilas, the Philokalia, Seraphim of Sarov) have been constant inspirations for me in my preaching ministry, not to mention the icons that are the only images before which I am able to pray.
2. East and West on the mystery of the Trinity
Let us begin our ascent by treating the mystery of the Trinity, that is, the highest mountain, the Everest of faith.  In the first three centuries of the life of the Church, as the doctrine of the Trinity gradually became explicit, Christians saw themselves exposed to the same accusation they had always leveled against the pagans: that of believing in more than one God, of being polytheists themselves as well. This is why the credo for Christians in all its various formulations for three centuries that began with the words, “I believe in God” (Credo in Deum), is adjusted with a small but significant addition beginning in the fourth century that would never again be omitted afterwards: “I believe in one God” (Credo in unum Deum).
It is not necessary to go over the path that led to this result: we can move forward immediately to its conclusion. Toward the end of the fourth century the transformation of the monotheism of the Old Testament into the Trinitarian monotheism of Christians had been completed. The Latins expressed the two aspects of the mystery with the formula “one substance and three persons,” and the Greeks with the formula, “three hypostases, one single ousia.” After a heated meeting, the process apparently concluded with a total agreement between the two theologies. “Can anyone conceive,” asked Gregory Nazianzus, “of a more complete agreement and a more absolute expression about the same thing, even if it uses different words?”
One difference actually did remain between the two modes of expressing the mystery. Today it is generally expressed this way: in their consideration of the Trinity, the Greeks and the Latins move from opposite poles: the Greeks move from the divine persons, that is from plurality, to reach the unity of nature, and the Latins, in contrast, move from the unity of the divine nature to reach the three persons. According to a French historian of dogma, “Latin theology considers personality as a mode of nature; Greek theology considers nature as that which is contained in the person.” 
I think this difference can also be expressed in another way. Both Latins and Greeks begin with the unity of God. Whether it is the Greek or Latin creed, it starts by saying, “I believe in one God.” But this unity for the Latins is conceived of as still impersonal or pre-personal. It is the essence of God that then becomes specified as Father, Son, and Holy Spirit, without of course being thought of as preexisting the persons. In Latin theology, the treatise “De Deo uno” (“On One God”) has always preceded the treatise “De Deo trino” (On the Triune God”).
For the Greeks, instead, the unity is already personalized, because for them, “the unity is the Father, from whom and in relation to whom the other persons are recognized” The first article of the credo of the Greeks also says, “I believe in one God the Father almighty,” but “Father almighty” here is not separated from “one God,” as it is in the Latin creed, but makes one complete unit with it. The comma does not come after the word “God” but after the word “almighty.” The meaning is “I believe in one God who is the Father almighty.” The unity of the three divine persons for the Greeks comes from the fact that the Son is perfectly (substantially) “united” with the Father, just as the Holy Spirit is united to the Son.
Either manner of approaching the mystery is legitimate, but today the tendency more and more is to prefer the Greek model in which the unity in God is inseparable from the Trinity but forms a unique mystery and flows from one single act. Using inadequate human words, we can say the following: The Father is the fountain, the absolute origin of the movement of love. The Son cannot exist as the Son if he does not first of all receive from the Father all that he is. John of Damascus writes, “It is because of the Father—because of the fact that the Father exists—that the Son and Holy Spirit also exist.”
The Father is the only one, even within the Trinity, absolutely the only one, who does not need to be loved in order to love. Only in the Father is this perfect equation realized: to be is to love. For the other divine persons, to be is to be loved.
The Father is an eternal relationship of love and does not exist outside this relationship. We cannot, therefore, conceive of the Father primarily as the supreme being and then recognize an eternal relationship of love in him. One needs to speak of the Father as an eternal act of love. The unique God of Christians is therefore the Father; he is not, however, conceived as separate (how can someone be called “father” unless he has a “son”?) but as the Father who is always in the act of generating the Son and giving himself to him with an infinite love that unites both of them and is the Holy Spirit. The unity and Trinity of God flow forth eternally from one single act and constitute a unique mystery.
I said that many today, even in the West, tend to prefer the Greek model (and I myself am among these). We need to add at once, however, that this does not mean renouncing the contribution of Latin theology. If in fact Greek theology has furnished, so to speak, the correct outline and approach for speaking about the Trinity, Latin thought, through Augustine, has secured its fundamental content and soul, which is love. Augustine bases his discussion of the Trinity on the definition that “God is love” (1 Jn 4:16), seeing the Holy Spirit as the mutual love between the Father and Son according to the triad of lover, beloved, and love that his medieval followers would make explicit and almost canonical. In this same line the theologian Heribert Mühlen has recently put forth a conception of the Holy Spirit as the divine “We,” the personified koinonia between the Father and the Son in the Trinity and, in a different way, among all those baptized in the Church.
The first one among the eastern theologians to acknowledge this contribution of Latin theology was Gregory Palamas who, in the fourteenth century, finally became personally acquainted with St. Augustine’s treatise on the Trinity. He writes,
That Spirit of the supreme Word is like an ineffable love of the Begetter towards the ineffably begotten Word himself. The Beloved Word and Son of the Father also experiences this love towards the Begetter, but he does so inasmuch as he possesses this love as proceeding from the Father together with him and resting connaturally on him.
The opening up of the issue by Palamas is being taken up today in another context by a noted Orthodox theologian when he writes, “ The expression “God is love’ means God ‘exists’ insofar as he is Trinity, that is to say, as a ‘person’ and not a substance. Love is not a consequence or a ‘property’ of the divine substance . . . but is what constitutes his substance.” This seems to me an explanation that is compatible with the definition that St. Thomas Aquinas, in the wake of Augustine, gives of the divine persons as “subsistent relationships.”
The difference and the complementarity of the two theologies are not limited, however, only to the manner of understanding the essence and the relationships internal to the Trinity. With certain significant exceptions on one side or the other, it is clear that the Greeks are more interested in the immanent Trinity, outside of time, while the Latins are more interested in the economic Trinity, that is, how the Trinity reveals itself in the history of salvation. The Greeks, in line with their own genius, are more interested in being and ontology, the Latins in its historical manifestations. In this light, one can understand the Latin habit of beginning the discussion about God with the treatise “On the One God” instead of “On the Triune God.” And we can also understand their reasons for wanting to maintain this tradition as a treasure for everyone. In the history of salvation in fact—as we will soon see—the revelation of the one God preceded that of the triune God.
The clearest sign of this difference in approach can be seen in the two different ways of representing the Trinity in Greek iconography and western art. The canonical icon of Orthodoxy, which has its high point in Andrei Rublev, represents the Trinity by the figures of three equal but distinct angels seated around a table. Everything about it makes a superhuman stillness and unity shine through. The history of salvation is not ignored as demonstrated by the allusion to the occasion when Abraham welcomes the three guests and by the eucharistic table around which the three are seated, but that all remains in the background.
In western art, from the Middle Ages on, the Trinity is represented in a completely different way. We see the Father with his arms extended, supporting the two arms of the cross, while a dove that represents the Holy Spirit hovers between the face of the Father and the Crucified One. The most famous examples are the Holy Trinity of Masaccio in Santa Maria Novella in Florence and of Albrecht Dürer in the Vienna Museum, but numerous examples can be found whether on the popular or artistic level. This is the Trinity as it is revealed to us in the history of salvation that has its apex in the cross of Christ.
3. Two paths still open
Let us take another step forward and attempt to see how the Christian faith needs to keep open and viable both paths to the Trinitarian mystery delineated here. To state it in terms of an outline: the Church needs to receive fully the Orthodox approach to the Trinity into its internal life, that is, in its prayer, contemplation, liturgy, and mysticism, and it also needs to maintain the Latin approach in its mission of evangelization to those outside.
There is no need to demonstrate the first point. In that regard, all we have to do is receive with joy and gratitude the very rich heritage of spirituality that comes from the Greek and Byzantine tradition and that various Orthodox theologians in recent times have defended and made accessible to the western public. A text from St. Basil expresses well the fundamental orientation of the Orthodox vision:
The path to the knowledge of God proceeds from the one Spirit, through the one Son, and to the one Father. Conversely, natural goodness, inherent holiness, and royal dignity come forth from the Father through the Only-Begotten and to the Spirit.
In other words, on the level of being and the coming forth of creatures from God, everything comes from the Father, goes through the Son, and reaches us through the Holy Spirit. In the order of knowledge, or of the return of creatures to God, everything begins with the Spirit, goes through the Son Jesus Christ and returns to the Father. The perspective in both cases is Trinitarian.
What I want to explain instead is why it is necessary today more than ever, be it in the East or the West, to know and to practice the Latin approach to the mystery of the one and triune God as well. St. Gregory Nazianzus, in a famous text, synthesized the process that led to faith in the Trinity this way:
The Old Testament proclaimed the existence of the Father in an explicit way, while the existence of the Son was proclaimed in a more obscure way. The New Testament manifested the existence of the Son while it suggested the divine nature of Holy Spirit. Now the Spirit is present in our midst and grants us a manifestation of himself more clearly. It would not have been appropriate, when the divinity of the Father had not yet been acknowledged, to proclaim openly the divinity of the Son, and it would not have been safe for the Son to lay on us the weight of the divinity of the Holy Spirit when the divinity of the Son had not yet been accepted. 
We see this same divine pedagogy practiced by Jesus. He told the apostles he was not able to reveal all the things that pertain to himself and his Father because “you cannot bear them now” (Jn 16:12).
It is true that we now live in a time in which the Trinity has been fully revealed, and therefore we ought to live constantly under this “trisolar light,” as some ancient Fathers call it, without losing ourselves in the contemplation of a “supreme being” God who is more like the God of the philosophers than the God revealed by Jesus. But what do we say about the non-believing, secularized world in need of re-evangelization that is all around us? Isn’t our world in the same condition as the world before the coming of Christ? Shouldn’t we, in facing that world, use the same pedagogy that God used to reveal himself to all of humanity?
We too should therefore help our contemporaries to discover above all that God exists, that he created us out of love, and that he is a good Father, who revealed himself to us in Jesus of Nazareth. Can we honestly begin our evangelization by speaking of the three divine persons? Wouldn’t this also be, to use St. Gregory’s image, putting a weight on people’s shoulders that they cannot carry?
One important thing needs to be noted. The Father who, according to Gregory Nazianzus revealed himself first in the Old Testament, is not yet the “the Father of our Lord Jesus Christ,” that is, a real father of a real son. He is not God the Father of the Trinity; that revelation only comes with Jesus. He is still a father in the metaphoric sense, in the sense of being “a father to his people Israel,” and for the pagans, the “father of the cosmos,” the “celestial father.” Even for St. Gregory, therefore, the revelation about God began with “the one God.”
There is a sense in which the word “God” can and should be used to designate what the three divine persons have in common, that is, the whole Trinity, whether we mean, as Scripture does and the ancient fathers did, a common element like “nature,” substance, or essence (2 Pet 1:4: “partakers of the divine nature” theia physis), or whether we mean, as John Zizioulas proposes, “being as communion.”
The Church needs to find a way of proclaiming the mystery of the one and triune God with appropriate categories that are understandable to the people of its time. This is what the Fathers of the Church and the ancient councils did, and it is in this above all that our fidelity to them consists. It is difficult to think of being able to present to people today the Trinitarian mystery with their same terms of “substance, hypostasis, properties, and subsistent relationships,” even if the Church can never abandon using those terms in its theological settings and in the places where the faith is studied.
If there is something that the experience of proclamation shows is still capable of helping people today—if not to explain, then at least to give them an idea of the Trinity—it is precisely what Augustine did in making love the centerpiece. Love is, in itself, communion and relationship. Love cannot exist without two or more persons. Every love is the movement of one being toward another being, accompanied by the desire for union. For human beings, that union always remains incomplete and transitory, even for the most ardent lovers. Only among the three divine persons is that union realized in such a total way that it eternally makes of the Three one single God. This is a language that people today are also able to understand.
4. United in worship of the Trinity
St. Augustine suggests to us the best way to conclude this reconstruction of the two paths of approaching the mystery of the Most Holy Trinity. If we want to cross over an inlet of the sea, he says, the most important thing is not to stay on the shore and strain our eyes to see what is on the opposite shore but to get into the boat that brings us to that shore. So too for us the most important thing is not to speculate about the Trinity but to remain in the faith of the Church, which is the boat that takes us there. We cannot embrace the ocean but we can enter into it; no matter how hard we try, we cannot embrace the mystery of the Trinity with our minds, but we can do something even better – enter into it!
There is an issue in which we find ourselves united and in agreement, with no differentiation at all between East and West: our duty and our need to worship the Trinity. Only in worship will we truly practice, not only with words but with deeds, the apophatism, that is, that rule of humble restraint in speaking about God, of saying without speaking. To worship the Trinity, according to a stupendous oxymoron from Gregory Nazianzus, is to raise up to God “a hymn of silence.” To worship is to recognize God as God and ourselves as creatures of God. It is to recognize “the infinite qualitative difference” between the Creator and the creature, to acknowledge it freely and joyfully, however, as sons and daughters and not as slaves. To adore, says the Apostle, is “to liberate the truth that is held captive by the unrighteousness of the world” (see Rom 1:18).
Let us conclude by reciting together the doxology that, from the most ancient times, rises up identically to the Trinity, both in the East and in the West: “Glory be to the Father and to the Son and to the Holy Spirit, as it was in the beginning, is now, and ever shall be world, without end. Amen.”
Translated from Italian by Marsha Daigle Williamson
 Orientale lumen, 1.
 Tertio millennio adveniente, 16.
 Quintus Aurelius Symmachus, Relatio de arae Victoriae, III, 10, in “Monumenta Germaniae Historica,” Auctores antiquissimi Bd.6/1, rist. 1984.
 For a critical collection of various theologies of the Trinity operative today in different Christian Churches, see Veli-Matti Kärkkäinen, The Trinity: Global Perspectives (Louisville, KY: Westminster John Knox, 2007).
 Gregory Nazianzus, Discourses, 42, 15 (PG 36, 476).
 Théodore de Régnon, Études de théologie positive sur la Sainte Trinité, vol. I (Paris: Victor Retaux, 1892), 433.
 Gregory Nazianzus, Discourses 42, 16 (PG 36, 477).
 See Gregory of Nyssa, Contra Eunomium 1, 42 (PG 45, 464).
 John of Damascus, De fide orthodoxa, I, 8.
 Augustine, On the Trinity, VIII, 9, 14; XV, 17, 31; see Richard of St. Victor, De Trin. III, 2.18, and St: Bonaventure, I Sent. d. 13, q. 1.
 See Heribert Mühlen, Der Heilige Geist als Person: Ich – Du – Wir (Munster: Aschendorf, 1963).
 Gregory Palamas, The One Hundred and Fifty Chapters, trans. and ed. Robert E. Sinkewicz (Toronto: Pontifical Institute of Mediaeval Studies, 1988), 123; Capita physica, 36 (PG 150, 1145).
 Jean Zizioulas, Du personnage à la personne, in L’être ecclésial (Genève: Labor et Fides, 1981), p. 38.
 Thomas Aquinas, Summa Theologiae, I, q.29, a. 4.
 See Vladimir Lossky, La teologia mistica della Chiesa d’Oriente (Bologna: Mulino, 1967) [original ed., Théologie mystique de l’Eglise d’Orient, Paris: Editions Montaigne, 1944]; Paul Evdokimov, L’Ortodossia (Bologna: Mulino, 1965) [original ed., L’Orthodoxie (Paris: Neuchâtel, 1959)]; and John Meyendorff, Byzantine Theology: Historical Trends and Doctrinal Themes (New York: Fordham University Press, 1974).
 Basil of Cesarea, De Spiritu Sancto XVIII, 47 (PG 32, 153).
 Gregory Nazianzus, Discourses, 31 (Theologica II), 26; cf anche Discourses, 32, (Theologica III).
 Augustine, On the Trinity, I, 6, 10: “The name ‘God’ indicates the whole Trinity and not just the Father.”
 John Zizioulas, Being as Communion: Studies in Personhood and the Church (London: Darton, Longman, and Todd, 1985.)
 See Augustine, On the Trinity IV, 15, 20; Confessions, VII, 21.
 Gregory Nazianzus, Carmi, 29 (PG 37, 507) (sigomenon hymnon).
 A famous phrase by Søren Kierkegaard in Sickness unto Death.