Two Bookends of Belief: The Trinity and the Incarnation

“The Church communicates salvation first of all by keeping and proclaiming the two great mysteries of the Trinity and the Incarnation, which are like the two ‘primary sacraments,’ and then through administration of the other sacraments.” —Pope Benedict XVI

LEFT: Szymon Czechowicz, “The Blessed Trinity,” ca. 1748. RIGHT: Bartolomé Esteban Murillo, “The Annunciation,” ca. 1660.
LEFT: Szymon Czechowicz, “The Blessed Trinity,” ca. 1748. RIGHT: Bartolomé Esteban Murillo, “The Annunciation,” ca. 1660. (photo: Public Domain)

Along the shelf containing all the things we need to believe, there are two bookends between which everything else may be found. Each is utterly indispensable to the other, and If we were to pull either one out, relegating it to some lesser shelf, the whole weight of Christianity would collapse, falling at once into a heap of ruins.

So, what are these two bookends on which everything depends? And why if they were suddenly to go missing would everything implode? The answer is not mine to give, nor has it been given by minds far more learned than mine; the answer is given by the Church herself, the only “the Church,” who speaks the mind of God in the distinctive accent of Jesus Christ. Her task is to tell the world about Jesus, whom the Father sent among us to live and to die.

This is her great commission, by the way, which she can only discharge provided the two bookends remain securely in place. Trinity and Incarnation — from the depths of which everything else stands revealed. Take a look at the end of Chapter 16 of the Gospel of St. John, where Jesus, despite having just told his disciples about the hour that has come when all will be scattered, leaving him seemingly alone, will nevertheless assure them that he is never alone. And why is that? Because the Father, his very meat and drink, is always with him. “I have said this to you,” he adds, “that in me you may have peace. In the world you have tribulation; but be of good cheer, I have overcome the world” (16:33). 

How can he possibly justify a claim like that? A mere mortal blithely announcing that he’s overcome the world? Where does such confidence come from? It comes from the Father with whom, from all eternity, he is most intimately and perfectly joined. The connection is an absolute and ontological one, not relative or operational; which is to say, it is forever rooted in and constitutive of the Godhead itself.

“When Jesus had spoken these words,” John tells us at the very beginning of Chapter 17, “he lifted up his eyes to heaven and said, ‘Father, the hour has come; glorify thy Son that the Son may glorify thee, since thou hast given him power over all flesh, to give eternal life to all whom thou hast given him. And this is eternal life, that they know thee the only true God, and Jesus Christ whom thou hast sent’” (17:1-3).

Here, unmistakably juxtaposed, are the two bookends. Omit one or the other and Christianity, as we know it, self-destructs.

Or, to take another still more striking example, that of the mysterious exchange at the beginning of John 14, where Jesus says things to his disciples of which they can make no sense whatsoever. “And when I go and prepare a place for you,” he tells them confidingly, “I will take you to myself, that where I am you may be also. And you know the way where I am going” (14:3-4). But, of course, they haven’t a clue concerning either of these things. It is Thomas who explains the predicament they all feel themselves to be in: “Lord,” he asks, “we do not know where you are going; how can we know the way” (14:5)?

Jesus then answers Thomas and his reply is among the most lapidary of all the sayings ascribed to Jesus: “I am the way, and the truth, and the life; no one comes to the Father, but by me. If you had known me, you would have known my Father also; henceforth you know and have seen him” (14:6-7). 

Everything we believe concerning our common faith thus turns on those two things. And all of Catholic theology will find its necessary nourishment only to the extent it is steeped in those two mysteries of faith. Which is exactly why, were they to disappear, vaporizing into thinnest air, Christianity would cease to exist. Knowing the Father is where we hope to go; knowing the Son, the man Jesus in whom that very fullness of divinity is pleased to dwell, is how we hope to get there. Getting to God, moreover, is not a roundabout way, but one that cuts directly through the Incarnate Word. How beautifully was this hope given expression by our late pope, now St. John Paul II, when, in the last hours of his life, he declared that “the whole of the Christian life is a great pilgrimage to the House of the Father.”  If that be true, then the only road that will lead any of us there is the one paved by the Son of God himself.  

Just as we know nothing of Christ, nothing of the mystery of his Incarnation, apart from God, the deepest secret of whose life is the Trinitarian ground of his being, so too we know nothing of that Triune life unless Christ were to come among us and tell us all about it. Indeed, to share it with us as a result of the frightful events of his own passion and death.  And so Jesus reveals the Father, even as his own self-revelation depends on the Father speaking his name from those same Trinitarian depths. Jesus becomes for us, then, the very invocability of God, to use an image drawn from a wonderful work by Joseph Ratzinger called Introduction To Christianity. The voice of the Father is given to us to hear only because it is first spoken through, mediated by, the voice of the son.

We should remind ourselves of these twin mysteries when, in the simplest and yet most profound gesture of piety, we make the Sign of the Cross to begin to pray. There is no more expressive symbol of witness to our faith than to sign ourselves with the truth of who God is — Father, Son and Holy Spirit — and the way in which the Son has come to meet us in and through the man Jesus, in order thus to take us home with him to the Father.