How many of you think about the doctrine of the Trinity on a regular basis? What about weekly? Or monthly? Full disclosure: I happen to think about the Trinity quite often because part of my work involves teaching theology at none other than Trinity College at U of T. So I’m obligated to think about the Trinity. But I suspect that, for many Christians, the Trinity doesn’t get a great deal of thought. I think that’s one reason why Trinity Sunday continues to be marked on the liturgical calendar: it compels all of us to take on the hard work—at least for one day—of making sense of God as three persons and one substance.

There’s another reason why Trinity Sunday is important. If you step back and take a bird’s eye view of the liturgical calendar, you’ll notice that the whole year has a trinitarian shape. It begins with Advent, a season of longing for deliverance, of longing to be reconnected to the source of our existence and the mystery of all things. That mystery is what Christian tradition calls God the Father. It’s a mystery that we can begin to fathom in the life of Jesus of Nazareth. From his birth and unremarkable upbringing, to his baptism, to his wondrous signs and prophetic agitation, to his arrest and execution, to his resurrection—his entire life in all its historical particularity reveals the eternal union of heaven and earth. That’s why Christian tradition identifies Jesus as God the Son. But the historical Jesus no longer walks the earth with us. He has resurrected and ascended. Nevertheless, his presence is with us everywhere in what Christian tradition has called God the Holy Spirit. Last Sunday was Pentecost when we celebrated the Holy Spirit. And today we put the three pieces of the puzzle together: Father, Son, and Holy Spirit. The remainder of the liturgical calendar, what’s known as “ordinary time,” is when we live into the fullness of the triune life of God.

What do I mean by living into the fullness of God’s life? I think it’s helpful at this point to quote the former Archbishop of Canterbury, Rowan Williams. In a short article titled “Father, Son and Holy Spirit,” the Archbishop reminds us not to think of God as “the name of a person like a human person, a limited being with a father and mother and a place that they inhabit.” Instead, Archbishop Williams says, God “is the name of a kind of life” that is revealed in three ways: “a source of life, an expression of life and a sharing of life.” The source of that life is the mystery of the first person of the Trinity. The expression of that life, the second person of the Trinity, is what is epitomized in the particular life of Jesus of Nazareth. And the sharing of that life throughout the world is the ongoing work of the Holy Spirit.

Archbishop Williams is making the radical claim that God is not a super being on high who responds inconsistently to our intercessions. Rather, God is a way of life in which we all participate. And if the Archbishop is correct—I’m convinced he is—then the doctrine of the Trinity is very important for thinking about how we ought to live, even in the mundane aspects of daily existence.

I’d like to suggest in conclusion that today’s Gospel offers a specific view of God’s life. In the curious interaction between Jesus and Nicodemus, Jesus identifies himself with the bronze snake that Moses put on high display during Israel’s period of desert wandering. The point, as I see it, is that God’s life is found in the desert, particularly in the circumstances that arise in the struggle for deliverance from bondage. The Israelites were enslaved in Egypt, and after much social conflict, they achieved liberation. But that meant leaving Egypt for the harrowing ordeals of the desert, where they faced thirst, starvation and other threats like deadly snake bites. And throughout it all, even at the lowest moments, God was present, leading them forward and ultimately out of the wilderness.

In our day, God is just as present in desert realities, in particular the deserts of racism, poverty and homelessness that many people are wandering through right now. We at St. Aidan’s have embarked on a journey of learning about the depth and complexities of racism and how we might appropriately respond. That learning, and the action we’re compelled to undertake, is more than just the right thing to do. It’s how we participate in the liberating life of God. It’s how the Trinity comes alive among us and in us. The expression of God’s life as liberation to those in the desert is what is epitomized in the life of Jesus of Nazareth. It has its source in the great mystery of all things, God the Father, and it’s a life shared universally in God the Holy Spirit.

I suppose what’s most important in all of this is that God’s triune life does not happen “out there” on a stage for us to observe from the bleachers. We’re part of it, in the midst of it. God is living, moving around us and among us in the struggle of those who suffer, particularly those stigmatized because of the color of their skin or because they can’t find adequate housing. And as we learn to be in solidarity, we join in the struggle. That’s why all of the learning that we’re doing—the examination of the hymns we sing, the language of our liturgy, our desire to decolonize our minds, our continued involvement with Out of the Cold, our concern that the Senate pass Bill C-15, our social justice Vestry motion against anti-Black racism that compels us to radical and uncomfortable action—all of this is an entry to participation in the triune life of God.

So today we celebrate God as Trinity. Let’s embrace this doctrine not as a confusing, irrelevant, metaphysical conundrum, but as an anchor for all that we may find ourselves doing in the struggle for justice in the deserts of the world. For that is where we encounter the living God.