The Trinity:
An Introduction

Ephesians 2:18-22; Matthew 28:16-20

By Rev. Kevin Chiarot

I. Setting

Bernard Lonergan, 20th C. Catholic philosopher and theologian, commented dryly that: "The Trinity is a matter of five notions, four relations, three persons, two processions, one substance, and zero understanding." Karl Rahner, another famous 20th c theologian, said: that if the doctrine of the Trinity were discovered to be false, the vast majority of Christian literature would remain unchanged. So, I might add, would the vast majority of Christian practice and speech. If God were to have 7 persons in his being, instead of 3, nothing would change for us. We'd have the same devotions tomorrow. Same passions.

We view the Trinity, if we think about it at all, as a strange, impenetrable mystery. A conundrum, largely irrelevant, and certainly impractical. It seems like a highly speculative distraction from the work of the gospel. Why can't we just stick the simple message of salvation? Plus, there's all this Jargon, all this extra-biblical language. The Word Trinity is not in the Bible. Nature, substance, persons, relations --- the Bible doesn't talk like this.

So if we do get around to the Trinity, its often treated as an add on, an optional add on at that. Besides, we live under the tyranny of the urgent, and the immediate, and the supposedly practical. As if high theology were not highly practical in itself. Sinclair Ferguson has said, concerning Jesus upper room discourse in John chapters 13-17, that marvelous window into our Lord's last evening with his disciples:

"When his disciples were about to have the world collapse in on them, our Lord spent so much time in the Upper Room speaking to them about the mystery of the Trinity. If anything could underline the necessity of Trinitarianism for practical Christianity, that must surely be it!"

Now, the Trinity takes time. There are no shortcuts around the work, no immediate, obvious cash value, no shining relevance to the great cultural battles the church faces. And we don't have time for the nuance, for the minutia, we have a lot of pressing matters. So its gets deferred – usually forever – for the whole of a Christian life.

It's hard to discern that anything pernicious is happening, because it looks like we are interested in God. There's a lot of God-talk. But, as I've said earlier in this series, we are really interested in the X part of God and X. Where X is usually some Christian thing. And X (whatever it is) X is enormous, and God thins out, and fades into the background.

We have little interest in his inner life and being as Father, Son, and Spirit. Thus, sadly, "Trinitarian," is not an adjective we use of ourselves, or our doctrine, or our churches. Nor would anyone outside think to use it of us. But if God, not God in general, but the Triune God, is our chief end, our goal, our delight; if seeing his face, if the vision of this glory is our destiny, then the Trinity must be our preoccupation.

The church is, even now, and we saw this in our NT reading, a Trinitarian dwelling place:

In him you also are being built together into a dwelling place for God by the Spirit. In Christ, we are a dwelling place for God the Father by the Spirit.

Thus, in our reading from Revelation, the temple is the Lord God Almighty and the Lamb, and, by the Spirit (water flowing from throne), we will see the face of the Triune God and worship. And this dwelling together, in praise and adoration, is ALL we will be preoccupied with for eternity. Trinitarian exploration is the only subject on the eternal curriculum. So it is fitting for us to cultivate delight now – even though exertion, labor, is necessary, if we are to reap an enlarged taste for and capacity to enjoy the Triune God.

Augustine: In his famous work, De Trinitate (On the Trinity) says: "in no other subject is error more dangerous, or inquiry more laborious, or the discovery of truth more profitable."

There is nothing more dangerous, more laborious, or more profitable than undertaking this task we begin today. But before we start, first, I want to encourage you. Whether you think of it or not, whether you realize it or not, if you are in Christ, you ARE immersed in the reality of the Holy Trinity. Paul: In Christ, we are a dwelling place for God the Father by the Spirit. You are already embraced by the Triune God. In the lovely words of Fred Sanders: we are compassed about by the Father, Son, and Holy Spirit. Not by God in general, but by this God. We start, with all of our ignorance and foibles and neglect, we start enfolded in the love of the Triune God.

As with early church, we experience the reality first, the detailed explanation, the technical issues, the clarity, come later. We are, then, for all of our indifference and weaknesses, not strangers to the Holy Trinity. What we are doing here then is seeking to clarify, to surface the reality we are already embraced by, that we might love and serve the Lord more fully, more robustly; that we might walk in the truth more richly. That's the setting.

II. The Significance

Our second point is the significance. What I want to assert here, is that the Trinity is not only relevant, it is of towering importance. There is no Christianity without it. We will do this with a few broad strokes. So broad, that we take these things for granted, if we don't overlook them completely.

First, then, this is the distinctively Christian doctrine. The 5th c. Athanasian (named after the defender of the Nicene Faith) Creed says this:

Whosoever will be saved, before all things it is necessary that he hold the catholic (small c, universal) faith. Which faith, except everyone do keep whole and undefiled; without doubt he shall perish everlastingly.

And the catholic faith is this: That we worship one God in Trinity, and Trinity in Unity; Neither confounding the Persons; nor dividing the Essence.

Leave aside the warning of damnation for now. It's not claiming you need to be an expert on the nuances of the Trinity to be saved – but it is saying a denial of the Trinity is a denial of the faith. The Trinity IS – in one sense -- the catholic faith. The distinctively Christian reality. This is what makes the Christian gospel Christian.

The identity of the God we worship, the identity of the Son he sends, and the relationship between the Father and the Son, in the Spirit – this makes Christianity Christian. And this article (doctrine), as the Athanasian Creed says, stands before all others. If we do not believe in THIS God, we are not Christians. We cannot get along with some generic thing called 'God.' Here's Calvin: when we start thinking about God w/o thinking of the Holy Trinity he says: "only the bare and empty name of God flits about in our brains, to the exclusion of the true God." What is flitting around in our brains?

Secondly, when we come to the Trinity, we are coming, not just to the distinctively Christian truth, but to the Supreme Doctrine. The great British theologian, John Webster, who died in 2016, said: There is a sense in which there is only one doctrine. The Holy Trinity in his inner life and outer works. That is all that exists. The Trinity in and of itself, and the Trinity in its works. The eternal processions in the being of God, and temporal missions of the persons of God in the world. The Trinity is not a tack on – the inner life, and the outer works, of the Trinity --- this is all there is.

There are zero non-Trinitarian facts and realities in the world. All topics – all things - derive from, and end with, this God. Holy Trinity orders and shapes (or should) all Christian discourse. Imagine a map of concentric circles, ever widening circles which include stuff not in the inner circles. In that map, the Holy Trinity is first and widest circle, and encompasses all the others. It gives us the widest angle view of the world.

So, while we rightly delight in God's works, in creation and redemption, it is crucial, that, above all, we delight in God, in and of himself. I won't repeat it here, but you all know the mental experiment where you think everything else OUT of existence. And what is left, the Holy Trinity, is more glorious, and more alive, than all you have thought out of existence.

Whom have I in heaven, but Thee? And besides thee, there is none upon the earth that I desire. My flesh and my heart fail, but God, the Triune God, is the strength of my heart, my portion forever.

Let's put this differently: Fred Sanders has said it this way: God's inner life is better than the good news. Better than the gospel. Because the gospel is but a means to an end (not American renewal). Namely, communion, in glory, with the Holy Trinity. God is (way) better than the gospel. The gospel is a temporary, remedial thing. God was God for Himself, enjoying his own blessed life, before all worlds, before there was a gospel, and He will be sharing that life and joy with the redeemed, long after there is a gospel.

Let me summarize from Scott Swain, professor at RTS: "The doctrine of the Trinity is the most sublime truth of the Christian Faith, and its supreme treasure." So, the Trinity is not only the distinctively Christian doctrine, but the supreme and most sublime doctrine. Thus, its significance.

III. The Statement

Finally, the statement. By which I mean that I desire to state the doctrine clearly. But first, let's quickly review all we've done so far in this series on God. We've spoken of God's aseity, that is his self-existence as the I AM. We've looked at his undivided unity, his infinity, his eternity, his unchangeableness, his impassibility, his omniscience. His glory. All of these attributes apply to the One, divine nature of God. They are ways of describing the essence, the identical essence, shared by the Father, the Son and the Holy Spirit.

So, there are not three infinities or three eternities, or three sets of knowledge, there aren't three powers or three distinct goodness.' Or three sets of holiness or glory in God. This would be the case if each divine person were like a human person, a stand-alone entity, like three separate people taking counsel and working together. Which is the way we tend to think of it. But – this may be surprising -- there are not three wills in the Godhead. There is one will, shared by the three persons.

All of this is to simply say, that, to this point, we've been looking at the undivided essence, which is shared – not duplicated or triplicated – but the identical essence which is shared by all three persons. It is this which is on display vividly in the OT lesson from Deuteronomy 6: 4 "Hear, O Israel: The Lord our God, the Lord is one." He is not merely the only God, he is the uniquely unified, undivided God. The Lord is One. And thus, we are to love him with our unified, undivided hearts: You shall love the Lord your God with all your heart and with all your soul and with all your might. And yet, as we will see, many texts point us to the reality of three persons in this one God. For example, our gospel lesson, speaks of baptizing in the name (singular) of the Father, and of the Son, and of the Holy Spirit. One name or nature of God, three persons sharing or partaking of that one name. This is why we make disciples, baptize and teach.

So, here's the statement of what we believe in its simplest form: God is three persons in one being. Or you could say three persons in one essence. Or there are three persons in the Godhead. So, for example, the WSC, after affirming that there is only one God, gives us this question and answer:

Q6. How many persons are there in the Godhead? A. There are three persons in the Godhead (one Essence, one Being); the Father, the Son, and the Holy Ghost; and these three are one God, the same in substance, equal in power and glory.

Now, let's deepen this just a bit today, from the Athanasian Creed (cited earlier). It says this: We worship one God in Trinity, and Trinity in Unity; Neither confounding the Persons; nor dividing the Essence.

Let's take this one small phrase at a time. We worship one God in Trinity. The one God, the strong, undivided, simple, uncomposed unity of which we have been speaking, is a tri-personal unity. One God in three persons. Next, the Creed says we worship the Trinity in Unity. This means the three persons are one, they are united in the one being of God. Indeed, they are united as the one being of God. The three persons are One God, and the One God is Three Persons. It's very important to grasp that there are not four distinct things we are discussing here. The three persons plus the one nature.

The eternal communion of F,S, and Spirit just is the One God; and the One God exists as the three persons. This is a great mystery, I know. And I know its intellectually challenging. I have stated previously, there is nothing wilder or more complex or more interesting than the Christian God. But, as a start, let's at least grasp this. We must always (always) move from the one to the three, and from the three back to the one. Call it the mysterious, and glorious, circle of the divine life. As Gregory of Nazianzus, the great fourth century theologian, who did so much to clarify and shape the church's understanding of the Holy Trinity, said:

No sooner do I conceive of the One than I am illumined by the Splendor of the Three; no sooner do I distinguish Them than I am carried back to the One. When I think of any One of the Three I think of Him as the Whole, and my eyes are filled, and the greater part of what I am thinking of escapes me. I cannot grasp the greatness of That One so as to attribute a greater greatness to the Rest. When I contemplate the Three together, I see but one torch, and cannot divide or measure out the Undivided Light.

We worship, and shall endlessly worship, that God. One three-fold torch of undivided light. Glory be to the Father, and to the Son, and to the Holy Ghost, the One God – as it was in the beginning, is now, and ever shall be, world without end, Amen.