Midway through his discourse, having spoken at length on the importance and necessity of purification and conversion—indeed, having purified his congregation by his preaching—St Gregory turns his attention to the feast itself, the manifestation of the eternal Son in his baptism by St John the Forerunner.
Who is the God they are remembering in this celebration? Who is the God to whom they are offering hymns and glory? Gregory immediately excludes two heretical positions—the position of Sabellius, for whom the three persons revealed in the biblical story are simply temporal manifestations of the transcendent Deity, and Arius, who divides the three persons, reducing the Son and Spirit to creatures made by the God the Father. As already noted, the latter is the real problem in the church of Constantinople. For several decades various forms of Arianism have dominated religious life in the capital. Between these two evils, declares Gregory, lies the true and authentic faith of the Church:
When I speak of God, be struck from all sides by the lightning flash of one light and also three; three in regard to the individualities, that is hypostases, if one prefers to call them this, or persons, for we will not struggle with our comrades about the names as long as the syllables convey the same idea; but one if one speaks of the essence, that is the divinity. For they are divided undividedly, if I may speak thus, and united in division. For the divinity is one in three, and the three are one, in whom the divinity is, or, to speak more precisely, who are the divinity. But we omit the excesses and omissions, neither making the union a fusion [Sabellianism] nor the division a separation [Arianism]. (39.11)
I am struck by the flexibility of Gregory’s vocabulary, a flexibility which he maintains throughout his orations when speaking of both the Trinity and Incarnation. We may employ different words to speak of the mystery of the one and three, but what is important is that they mean the same thing. As we will see when we come to the Theological Orations, Gregory is very much aware of the limitations of our theological language before the mystery of the ineffable Creator.
But the Trinitarian rules are clear: the persons of the Godhead are irreducibly distinct; each is fully and completely divine, each possessing the one indivisible divine essence. How then are the divine persons distinguished from each other? By their mutual relationships and defining properties:
The Father is a father and without origin, for he is not from anyone. The Son is a son and not without origin, for he is from the Father. But if you take it to mean an origin in time, he is also without origin; for he is Creator of time, not subject to time. The Holy Spirit is truly the Spirit sent forth from the Father, yet not as a son or through begetting but through procession, if indeed one must make some innovation in words for the sake of clarity. Nor does the Father cease to be unbegotten because he has begotten, nor does the Son cease to be begotten since he is from the unbegotten—how could that be?—nor does the Spirit change either into the Father or into the Son because he proceeds or because he is God, though to the godless this does not seem to be so; for the property does not shift. For how could it remain a property if it were shifted and changed? (39.12)
St Gregory knows that his presentation of the Nicene understanding of the Holy Trinity challenges the catechetical instructions that many of his catechumens have received. His teaching must have generated dozens of questions in their minds. But his task today is not to answer all of their questions but to introduce them to the true God in whose Trinitarian Name they will soon be baptized, if they so choose. Who is the Father? The one God who eternally begets the Son and breathes out the Holy Spirit. Who is Jesus Christ? The divine Son who is eternally begotten by the Father. Who is the Holy Spirit? The divine hypostasis who eternally proceeds from the Father. Three persons, one divinity—that is all they need to know and confess.
Yet it all sounds very abstract (and it is), and so the Theologian immediately returns to the biblical story of salvation. “What is the the great mystery concerning us?” he asks. His answer:
Natures are made anew; God becomes human; the one who “rides on the heaven of heavens in the sunrise” of his own proper glory and splendor, is glorified in the sunset of our ordinariness and lowliness, and the Son of God allows himself to become and to be called Son of Man: not changing what he was—for he is changeless—but taking on what he was not—for he loves the human race—so that the incomprehensible one might be comprehended, associating with us through the medium of flesh as through a veil, since it was not proper to a nature subject to growth and decay to bear his deity in its pure form. For this reason, what could not be mixed has been mixed: not simply God and change, not simply mind and flesh, not simply the timeless one and time, not simply the uncircumscribed and measured limit, but also birth and virginity, dishonor with the one who is higher than all honor, impassible being with suffering, immortal substance with decay. For since that clever salesman for evil thought he was invincible, deceiving us with the hope of being gods, he is himself deceived by the screen of flesh, and thinking he was attacking Adam, he encountered God. In this way the new Adam succeeded in saving the old Adam, and put an end to the condemnation of the flesh; death, in that flesh, was put to death. (39.13 [Daley translation])
As in Oration 38, we see the employment of paradoxical expressions to speak of the mystery of Incarnation. God assumes that which he is not, not only corporeality and creatureliness but dishonor, decay, and unjust punishment. He enters into the fullest kind of solidarity with sinful humanity. In Jesus Christ the transcendent, ineffable Creator becomes comprehensible, tangible, graspable. Perhaps St Gregory had this Scripture in mind when he composed his oration:
That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, concerning the Word of life—the life was manifested, and we have seen, and bear witness, and declare to you that eternal life which was with the Father and was manifested to us—that which we have seen and heard we declare to you, that you also may have fellowship with us; and truly our fellowship is with the Father and with His Son Jesus Christ. (1 John 1:1-3)
St Gregory does not elaborate on the “knowability” of the unknowable God in and through the Incarnation, as we find, for example, in the theology of T. F. Torrance. That is a theme I’d like to explore on another occasion. But once again we see powerful testimony to Gregory’s unitive christology. Human salvation requires the author of the human story to become an actor within that story. Only thus can death be destroyed and human nature renewed. How does Christ destroy death? Here St Gregory invokes a metaphor that appears to have been popular in the 4th century: by cloaking himself in human flesh, God tricks Satan into arranging the innocent Christ’s unjust condemnation and crucifixion. St Gregory of Nyssa employed a similar figure in his Great Catechism:
For since, as has been said before, it was not in the nature of the opposing power to come in contact with the undiluted presence of God, and to undergo His unclouded manifestation, therefore, in order to secure that the ransom in our behalf might be easily accepted by him who required it, the Deity was hidden under the veil of our nature, that so, as with ravenous fish, the hook of the Deity might be gulped down along with the bait of flesh, and thus, life being introduced into the house of death, and light shining in darkness, that which is diametrically opposed to light and life might vanish; for it is not in the nature of darkness to remain when light is present, or of death to exist when life is active. (GC 24)
Satan undoes himself and all of his work by attacking directly the invincible Word hidden deep in the flesh. Just as Satan deceived the first Adam, so he is himself deceived by the the New Adam. Death swallows eternal life and is destroyed from the inside. And so the curse incurred in the garden is reversed.