Preached on Sunday, June 15, 2025, the First Sunday after Pentecost: Trinity Sunday, at Trinity Cathedral, Little Rock.

From Paul’s letter to the Romans: “We boast in our sufferings, knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not disappoint us, because God’s love has been poured into our hearts through the Holy Spirit that has been given to us” (Romans 5:3–5).

I have two items on my agenda for this Trinity Sunday sermon: first, Trinity the doctrine, and second, Trinity the Cathedral.

So, first, let’s talk doctrine.

The Christian doctrine of the Trinity is Mystery. As far as doctrines go, this one seems to be hidden behind a cloud of holiness. Imagine a good dose of incense, preventing us from seeing this doctrine clearly: that’s Trinity.

Christian history has been marked by various attempts at articulating the doctrine of Trinity—not explaining it, and certainly not explaining it away, but articulating it.

In 325 AD––1,700 years ago next month, in fact––the Council of Nicaea took the first collective stab at it. We’ll recite the fruits of their labor in a few moments: “We believe in one God…the Father, the Son, and the Holy Spirit.” And each is no less God than the other: “light from light, true God from true God.” You know the rest.

Augustine of Hippo, the fifth century African bishop, gave it a go himself, helping us to see more clearly the persons of the Trinity in their relations: “relations of opposition” he called them, distinct relations between the Father, Son, and Spirit. The Father begets the Son, the Son is begotten of the Father, and the Spirit proceeds from both the Father and the Son. 

Thomas Aquinas, the thirteenth century Dominican friar, contributed much to the conversation in his own day, too, giving us some terms that help name just what it is that we mean by Trinity: “subsistent relations,” he called them––independent relations––between Father, Son, and Spirit, while still consubstantially remaining one God.

Now, we give thanks for these doctors of the Church, and the many others like them, who have helped us reach toward Trinity. But we have to remember that the doctrine of Trinity is not fundamentally about articulating something, or defining something––not first and foremost, anyway. First and foremost, the doctrine of Trinity is about Mystery, holy Mystery.

Now, when we say that the Trinity is about Mystery, that doesn’t mean that we can’t know anything about our Holy God. As our Collect for today had us pray just a few moments ago, God has given us grace “to acknowledge the glory of the eternal Trinity.” By God’s grace, through Scripture, we know Trinity to be true. And, as John’s Gospel tells us, the Holy Spirit leads us into the truth that we could not bear before. No, when we say Mystery, we don’t mean that God is unknowable. It means that “God is always beyond our grasp.” God is always more. God can be known truly, but never fully––not now, anyway.

So, ultimately, our Triune LORD is not a puzzle to be solved but a Mystery to which we are drawn, a Mystery to be adored––always humbling us, always resisting being tamed by us, always putting us on our knees in faith and worship. And that is where the quest for true understanding begins: “faith seeking understanding.” This is what we mean by “Mystery.”

In part, this is what Paul is getting at in our passage from his letter to the Romans. This is what we mean by the Christian life. “We boast in our sufferings,” he so boldly writes “knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not disappoint us, because God’s love has been poured into our hearts through the Holy Spirit that has been given to us” (Romans 5:3–5). With God’s love in our hearts by the Holy Spirit, we persevere toward God in hope, day by day, year by year, until finally, we see God in His one and eternal glory: Father, Son, and Holy Spirit.

Now, let’s talk Cathedrals. After all, Trinity Sunday is also a day for us to celebrate this congregation, which bears the title “Trinity.”

When Bishop Henry Niles Pierce named this Cathedral “Trinity,” he surely had in mind everything we’ve said about Christian doctrine thus far. In one way, Bishop Pierce was signaling that this Cathedral would have a particular flavor of piety: a piety with a firmly held grasp on the tradition of the Church, of saints in ages past reaching toward the reality Who is God, helping us to articulate the reality Who is God. Just look up and around and you’ll find some of these ancestors of ours, etched in colored glass: Queen Elizabeth I of the sixteenth century, William Temple of the twentieth century, the apostles of the first century. Just look down at our kneelers and you’ll find some other companions of ours: Deans and Bishops of ages past and congregations from across this diocese. For us to bear the name “Trinity” is to be reminded that we stand in a tradition of people who, in their faith, have sought to understand. And our faith today is surrounded and bolstered by their witness.

But in another way, and perhaps a far more profound way, by naming this Cathedral “Trinity,” Bishop Pierce was signaling that this Cathedral would be caught up in the reality Who is God and the reality of our life in relation to this God. My theology teacher in seminary, Kate Sonderegger, put it this way: “the pilgrimage to the Mystery of the Holy Trinity begins in the temple” [1]. Here at Trinity, we make our pilgrimage to the Mystery of the Holy Trinity. What we do here in this place––in every Christian congregation, really, but especially in this one––is draw ever closer to the reality Who is God.

Even through our sufferings of knowing God only in part, we at Trinity might so boldly say that we “boast” in our sufferings, “knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not disappoint us, because God’s love has been poured into our hearts through the Holy Spirit that has been given to us” (Romans 5:3–5). With God’s love in our hearts by the Holy Spirit, we persevere toward God in hope, day by day, year by year––now for over 140 years––until finally, we see God in His one and eternal glory: Father, Son, and Holy Spirit. 

So, as the prophet Hosea once put it, “let us press on to know the LORD” (Hosea 6:3). Let us lock arms together here in this place, in this, our pilgrimage toward the Holy One. And let us pray that God might keep us steadfast in this faith and worship until, at last, we see Him. Amen.

[1] Katherine Sonderegger, Systematic Theology, Volume 2, The Doctrine of the Holy Trinity: Processions and Persons (Minneapolis: Fortress Press, 2020), 1.