The Christian theologian is tasked with the humble calling of speaking about God. If he is any good, his meditations on the sacred Trinity materialize not just as dogmatic assertions of the faith, but as some understanding that corresponds to God in himself.
Too little are we startled by how strange this is. Here stands a man we have dignified with the name of able theologian. He begins from the creaturely reality of Scripture. His field of discourse is populated with creaturely terms pressed to the service of unveiling divine mystery. If he is lucky, he concludes with some happy gains of understanding. And all this is but finite knowledge of a created intellect fed with the material world. In short, out of creaturely reality, by way of creaturely analogy, the theologian derives creaturely understanding. He waves about and says he’s got some knowledge of God. Some guts he has.
All great theologians have such guts. An instance: Thomas Aquinas commences his systematic treatise on the sacred Trinity with nothing more than a line about a man saying he “proceeded from” God the Father (ST I q 27 a 1, quoting John 8:42). From this we are to believe there is an eternal Son of God eternally proceeding from God the Father, and we are to gain some understanding of this—all thanks to this man, Jesus of Nazareth, as he is offered to us under the testimony of creaturely Scripture. And not this only: the Father speaks all three divine persons in this creature Jesus Christ. Out of this narrow humanity we must confess God is Trinity, and our faith seeks and acquires increasing understanding of divine mystery.
Is This a Fancy Move?
How can a creature, as presented under special revelation, sustain this burden? How can he be the source of our knowledge and understanding of the eternal God Father, Son, Spirit? Not infrequently, many are led to suppose that at least part of an answer to these questions and part of our trinitarian treatment as a whole requires us to perform something like a “move,” a bit of jiu-jitsu to free us from this scrape. The scrape is of course the fact that we are creatures and we are talking about God. What is further, we are not dealing with his essential attributes (absolute perfections which we find faintly in the created order), but God wholly englobed in himself as the eternal Trinity. There is no representing the Trinity itself in the created order. Well and good, many suppose; if we cannot do it here, then we shall simply do it there. We must only shift from created economy to the divine realm, where we perform our theology proper. Thus, we upgrade from created economy to occupy the divine transcendence, we translocate from below to above, from the free, gracious economical revelation to the immanent Trinity himself.
Among those regularized into the faith by early catechesis, such a “move” is in fact never taken; knowing God as Trinity, for the average Christian, is automatic and not discernibly different from the normal procedure for discovering anything unknown, though with the added intuition that God is always somehow more than one imagines, that he resists an easy meeting like we have at coffee shops or Sunday dinners. This is a good and earthy notion and shouldn’t be set aside in the technical discipline of theology. But in fact, this seems to be what happens as soon as someone enters the trial of theological training; suddenly, for those with some experience in the discipline, the situation is now fraught, and a “move” becomes needful.
For the professional academic, the “move” consists in the answer to a methodological problem rolled out at the head of trinitarian discourse, a priori. It is the answer cast rather unthinkingly to functionally transit between economic revelation and immanent Godhead, by arguing perhaps their convergence, meaningful identity, or delicate balance, so making peace between them. Over the course of the last century, the way this has largely played out has disassembled trinitarian theology, rather than magically girded it with renewed strength and insight. While talk about the created economy and immanent divinity is meaningful, of course, such a move between them is hardly adequate and, if adopted, frequently betrays that one is better suited to some other art or skill.
The Christian theologian doesn’t trade in “moves.” It’s simply not his coin. He is not a great proficient in transcending the economy. He has not outstripped the earth by mental prowess or willful power. He occupies it, whistling a tune and hands pocketed; he does not play at farce nor is he troubled by the babble then in vogue. He is studied and habituated to knowing God, from his stance among the stones. He can praise God there. He is unafraid to do so with children. He knows he cannot transcend the created realm, and that confusion happens if he tries (Gen. 11:4, 7).
No indeed, in our race to God we do not leave the created realm in the dust. We rather find ourselves ever within the economy, here in this life; and even in the next, the infinity of divine mystery does not collapse into our searching hands. Rather, we are always more deeply expanded into the divine, as a ship chases the horizon upon the sea but finds it never closer to being had in hand, no matter the progress made. In this life, however, we simply abide at the locus of Christ as he is taught us in divine revelation. God “in himself” escapes us, absolutely. Our knowledge remains a knowledge outside him and has in no sense entered within. We merely find this God, here in this life, in the being-true (esse verum) of our knowledge garnered from his effects, up to and including the sacred text. Never knowing God’s being (ipsum esse subsistens), never knowing his essence (essentia), we are merely knowing the truth (vera est) of the judgment we make about God, when we utter, for instance, “God is.”  Any theological understanding that follows from the judgment of faith is an understanding of creatures correspondent to God himself; this understanding may then be judged as true of God by faith. The structure of all this is cast concretely by Lateran IV (1215): in every similitude, there is an ever-greater dissimilitude. This articulates the dual function we perform of affirmation and then negation, and it permeates the whole of trinitarian discourse. But notice that nothing of the movement throughout this structure has risen above the level of the simple Christ held out under the sacred page.
Some Explanation for How Our Trinitarian Theology “Can Be So Creaturely”
None of the above is a dodge. Neither is it a craven bowing into silence, gilded perhaps with some shiny and performative piety. Nor does all this lack explanation—we can provide a robust account for the fact that our understanding which corresponds to God is solely founded within, sweeping through, and concluded internal to the realm of the economy. What is some explanation for the fact we obtain creaturely knowledge of the divine mystery thanks ultimately to a creaturely reality—that reality being Christ as offered in Scripture? “Explanation,” as opposed to what we might term “justification.” This last needs no other answer than that of St. Augustine: legitur, “it is read” in the divine books. The divine authority of special revelation is the first and final justification for all trinitarian discourse, and that justification is never positively advanced by any explanation to be offered or understanding gained.
Turning away from the question of any justification, the rough elements of an explanation boil down to this: Because the human being of Jesus really terminates in, depends upon, or participates the divine Son distinctly, it is the Son’s own image or similitude. Thus the man Christ, as offered under the divine testimony, is where we know that there is a divine Son eternally, and therefore is the place for gaining some trinitarian understanding. This is why the point of departure for all trinitarian theology is the divine testification to the man Jesus, who is the terminus of the Son’s mission.
We may articulate this much further of course—a few bits as follows. The divine eternal Son, distinct from Father and Spirit, is in his humanity as a “cause is in its effect,” to use the technical language. Or to put it in the language of metaphysics, the Son is within or internal to the created being of the effect, on account of the fact that the effect really participates in the Son’s own proper divine being. This effect is not merely nominally applied or appropriated to the Son as his: it is not “his” by feat of our mentally intending it to be so. The eternal and divine Son lifts this effect up into himself truly, and thus the effect receives his special signature of ownership; it is to be remarked that this signature is nowise other than the signature of God. Note that the eternal Son is not merely “made manifest,” “visible,” or “known” in and by the created effect—he is and must be present anterior to all of this, thanks to which all these follow as the Son is shook forth into the world, shining and glorious before our eyes in transfigured human nature. Said otherwise, the real participation of the effect (the human being of Jesus) in the Son means that the Son is interior to or inlying the effect. On account of this, the effect, in its whole being and all of its subsequent activity (also in giving itself up for our knowledge), is the presence and activity of the Son properly speaking and really distinct. This “use” of the created effect by the divine person is often described more or less helpfully in terms of “instrumentality,” because the created being is sanctified unto this only divine person, enables or equips him for such tasks proper to an individual with real human nature, and remains set apart through the perdurance of that creature as the presence and action of that only person, truly. Because of the divine person’s presence in the effect, all that the creature is and so does in the narrow of its very creaturehood is the being and doing of the person in the expanse of his eternity.
The presence of the Son in the human being of Jesus is in distinction to the essential presence of God in the being of every creature. The reason for this distinction is patent enough. Unlike all other creatures, this created effect of Jesus (in its entire substance) really terminates in, depends upon, or participates in the Son really distinct from other divine persons. Studied theologians will recall the basic lines of the resolution to a (hypothetical!) problem peddled about today, which opens its mouth in objection here. The “problem” is supposedly entailed by another basic axiom of orthodoxy: opera ad extra indivisa sunt, the external effects are undivided or essentially caused, and therefore speak only of the essential, absolute perfections of Godhead, never of one divine person distinctly—for each and every person just is the absolute Godhead himself. The problem objects that such an axiom both contradicts logically and makes metaphysically impossible the exclusivity required for a created effect to be proper to one only person distinctly. But this is entirely puerile. Indeed, the humanity of Christ is an effect commonly principled by all three divine persons (as all creatures are); in this, it is created indivisibly by them (opera ad extra indivisa sunt). But the indivisa axiom poses absolutely no problem for the real participation of an effect in some one divine person as really distinct from others. The external making of the effect is indivisible, and the effect is the realized similitude of this, not that, divine person, because properly speaking it is “where” the effect terminates that determines its similitude. In short terms, the similitude is controlled, or rendered such a similitude, thanks to what that effect is really related to, not really principled by. The effect does not “look” any different in its perfections thanks to this difference of its termination in some one divine person; it is however the real participation in personal being and so is the being and doing of that person in the economic realm. This is the fundamental metaphysical explanation for how a created effect, whether the humanity of Christ or any other effect of a divine mission, can truly participate in one divine person really distinct from other divine persons; it is how there may be a man on the earth we worship as the Son, and how I may be implanted by the divine persons and commune with each of them and all of them as really distinct objects of my whole affection. Likewise, it is the fundamental way of holding together both equally basic commitments of all Christian orthodoxy tout court: the absolute divine simplicity of the divine essence, which commits us to the indivisa axiom whereby every and all created effects show us only something of the essence of God himself; and the eternally real distinction of divine persons as well as the incarnation of one only who dies for me as really distinct from the other two.
Further technicalities of this explanation must be left aside for another day. Exploring them renders the explanation more palatable but likewise challenging to follow. Given what has been said, I here simply note the unavoidable need for the addition of special revelation to attest to the fact that “truly this is the Son of God.” The participation of human being in the Son results in a man who is the similitude of the Son alone; nevertheless, the humanity of Jesus as such is wholly insufficient as a point of departure for our knowledge of the Trinity, except there be the sacred divine testimony to this. It is the Scripture as it tenders us the man which is our point of departure—
What is the reason for this “insufficiency” of the man Christ, except there be divine revelation? It is thanks to the simple fact that while this man Jesus is indeed the similitude of the Son, this truth cannot be derived by any perfection or attribute about the Galilean. I may have his face pressed hard against my own so that I breathe his breath, but must still hear the voice of God in my ears if I am to give him my life. Flesh and blood has not revealed this to me; for whatever absolute perfection may be and is found among creatures finds itself eminently in the divine essence, indivisibly the same as each one divine person. In short, all of what a created effect is, therefore all knowledge of a created effect, speaks to us of what is absolutely common to the divine persons, absolutely the divine essence itself. Pressing upon a creature with my intellect gives way to nothing but knowledge of absolute divine perfections, and nothing further. This is always the case. This is no matter what that creature is, up to and including the sacred humanity of Jesus. We are always in the position of John the Baptist: we did not know him, except that God testified (John 1:33). So likewise I cannot assent to this in faith, unless I have the light of Scripture dawn upon me; through this sanctified and holy thing called the sacred passages I am led unto new judgments wholly beyond what results from the nonsacred source of natural creation.
We cannot indulge any frustration at the economical way of our trinitarian discourse. Trinitarian theology is a mode of humility and requires that we act like humans and recall we are intellects in dust. If we swell and suppose we have reached beyond the economy, then we have ceased to function truly and are not knowing God, no matter what we have offered up. In such a case, what we have presented, what we have knowledge of, is not God the holy Trinity, but a god of human making, imaged as our likeness. All gods, no matter how fashionable, must fall before Jehovah (1 Sam. 5:3)—theologians must be pitiless if they discover such gods in the pages of their books. Nonetheless, when functioning rightly, we may obtain knowledge here below that is meaningful, true, and enough for life and divine praise that is owed God by virtue of who he truly is.
RM Hurd is a systematic theologian whose area of expertise is doctrine of God, specifically the Trinity. His primary training is in the high medievals and early modern scholastics as well as the twentieth-century ressourcement movement. His main project is writing a robust systematics of the Trinity; he also teaches systematics on God as a teaching fellow with The Davenant Institute .