At St. Andrew’s Episcopal Church in Nogales, AZ, once a month, miracles happen. Once a month, the church hosts the St. Andrew’s Children’s Clinic, where American doctors and nurses and health care professionals of all kinds come and give free medical care to handicapped children from Mexico. These children are the poorest of the poor, unable to afford the kind of lifesaving treatments that could give them new hope. But once a month they get a day pass to come into the US, their families come with them, and they get the care they need.

On the one day a month when this happens, the whole church is set up as a clinic. In the sanctuary there are pediatricians, in the narthex are physical and occupational therapists. In the chapel are teachers for visually impaired kids. In a mobile home out back is a clinic for hearing-impaired kids. In the sacristy they have clinics set up for prosthetic limbs and orthopedic shoes.

Every square inch of the church is converted to a medical clinic, and it takes an army of people to run it – people to set up and take down all the equipment, people to give the medical care, people to donate supplies, people to interpret, people to make lunch for all the workers.

And they see miracles – oh, they see miracles. I’ve gone there several times with our youth group and others, and the first time, I heard a story from Deacon Mike Meyers. His day job is as the owner of an orthopedic shoe store. Someone invited him to come down and see the clinic, so he brought some shoes along and went. So he was set up in the sacristy, and a family wheeled a little girl in, in a wheelchair. He looked at her, said, I think I have some shoes that will fit you, he put them on her. He felt her toes, and said, yes, I think those fit you. Now stand up and let’s see. She stood up, and he said, that’s good, now walk a couple of steps and we’ll check the fit. She walked a couple of steps, and he said, yes, I think those shoes will do.

And then he looked up and realized that everyone in the room was crying. That little girl had never walked before.

It was a miracle – God’s love in action – the simple gifts of a variety of people made that miracle happen. It wasn’t a supernatural miracle (though I have seen supernatural miracles), it was the church in action.

And when you think about it, that miracle was way bigger than Mike Meyers. It took all those folks to make this miracle happen – the cooks, the setup crew, the church, the people who raise the money, people who serve on the board. And more than that, it took the family of this little girl, who never gave up, who made the difficult and harrowing trip each month to get her the care she needed. And it took the little girl herself, who accepted a gift and had the courage to willingly try what she had never tried before. Every single person in that story was an agent of God’s kingdom, working together to give their different gifts, coming together as one to make God’s love manifest in this world by making a miracle happen. All had different roles, all had different gifts to give – and because of them all, a little girl learned to walk, and you and I are here to know about it and file it away and remember that God is truly present here on this earth with us.

Today is Trinity Sunday, when the church contemplates the mystery of Holy Trinity – God who has revealed self to us in three persons: Father, Son, and Holy Spirit. You may wonder what that has to do with the clinic in Nogales – well, we’ll get to that.

Now if you’re like me, this is a doctrine you don’t, can’t possibly understand. It takes a lot of very careful language to understand the Trinity, and even then we can only come close. If you want to see the best explanation, you can look at the Athanasian Creed on page 864 of the prayer book. But if you come away from reading it telling me that you have a complete understanding of the Trinity, I won’t believe you. None of us humans, with our finite minds, can understand the infinite. How can something be one in three and three in one? People have tried many different ways to understand it, and have offered lots of bad analogies: like the idea of water, that could appear as ice or liquid or steam, but it’s all still water. Or the idea that I’m one person, but some people see me as a priest and two people see me as a mother and one person sees me as a wife, but I’m still the same person, just taking on different roles. Let’s be clear – those are not good analogies – those are both just examples of the same thing appearing in three different ways, as if God just goes around doing things and we give him a different name depending on what hat he happens to be wearing.

But the mystery of the Trinity is that it’s not about one-ness; it’s about three-ness, about diversity. But it’s also not just about diversity and three-ness; it’s also about unity and oneness. The doctrine of Trinity says there are three distinct persons in the Godhead: Father, Son, and Holy Spirit, but they are one in substance, one in will. How can this make sense?

To give it a little context, let’s look at the beautiful picture on the screen – one of the most famous icons in Christian tradition – Andrei Rublev’s icon of the Holy Trinity. In this illustration, you see them at a table together, three persons who are distinct from each other, dressed differently, but you can’t really tell them apart, can’t imagine that one is more important than others; they are all distinct but equal. They’re neither male nor female – they’re either, or both. They sit at the table and look at each other with gazes of love – each one looking at another, no duo any stronger than any other – all three love each other intensely.

This illustration tells us something important about the Trinity: it tells us that God is a community of love. If there were only one figure, this would not be a picture of love. If there were two figures, this might be a picture of a relationship, but a relationship that no one else could participate in. Because there are three figures, you can see that they love each other, equally, and their love binds them together as a unity out of diversity.

With me so far? Here’s why this is important.

We say that God is love. But love is not an abstraction. There is no such thing as love that just floats around in the air without someone doing the loving and someone being loved. Love is active, love is specific, love is not a feeling but an exercise of the will, love is a decision to care about someone so intensely you will do anything for them. Love requires a Lover and a Beloved. Without persons loving, there is no love. Because there are three figures here, love flows between them.

What I’m describing to you is the Social Doctrine of the Trinity, a doctrine championed by great contemporary theologians like Juergen Moltmann and Miroslav Volf. It tries to explain not what the Trinity is, but why it matters to us.

To me, the Social Doctrine of the Trinity tells me why Trinity is not an abstraction, but actually incredibly important to us as Christians and as human beings. What’s important is that God encompasses a community of pure love.

If you’re going to make the argument that God is Love, that means that from before time began, there was a community in God, a community of Lovers and those Beloved. But not a community of three Gods; a community of three persons united in substance and will so that the love that flows between them is perfect, eternal. When we say that Jesus was the only begotten Son of God, we are saying that Jesus the Son was born out of love, that he existed from before time because God is Love; and when we say that the Holy Spirit proceeds from the Father and the Son, we are saying that the love of God is more than a duality of mutual admiration; the love of God is a community of love. It is love that respects the individuality of each person at this table in this icon, but it is love that binds them together in a unity of will, a unity of substance.

Here’s what else is important about that. Take another look at the icon. There are three persons sitting around a four-sided table. There is room at the table for one more. In this picture, the open side is our side. We are standing here, this table open to us, receiving an invitation to join the Father, Son, and Holy Spirit at their table of perfect community, perfect love. This community of love that exists within the heart of God encompasses us too. In fact, Christian theology says that because God is love, God is entirely love, that creation happened because God’s love spilled over. God created us and this world and the planets and the stars out of an excess of love, and the love that exists between the Father, the Son, and the Holy Spirit is so big that it can’t be contained within them – it extends to us too.

God can’t help but love us, God can’t help but invite us to this table, God yearns for us to be part of that community of love, that’s why Jesus came to find us when we were lost and bring us home, that’s why the Holy Spirit is still present and active in this church, that’s why we are adopted as God’s children through the sacrament of Holy Baptism that gives us new birth from above; it is all because of God’s eternal love.

And one more thing. Because God is a unity of love out of a community of diversity, that’s what we are called to be too. We are made in the image of God, and that means we are made for relationship, we are made for love. When Jesus commanded us to love God and love our neighbors, he wasn’t just imposing new rules on us. He was saying, be who you are created to be. Become who you are.

We are born out of love and we are brought together in love, and as a church we too are called to be a unity born out of diversity. We are called to respect and honor each other’s differences – that’s our diversity. At the same time that we exist because of, and for the sake of love. That’s our unity.

That clinic in Nogales, where one day a miracle of love became manifest? That miracle was born out of a community of diverse talents and gifts. Doctors, accountants, cooks, shoe store owners, interpreters, people who do setup and take down – every single member of that community was valued and essential – every single member of that community helped that miracle of love become manifest. Out of that community, love was created. Out of that community, love was given to one little girl, to the glory of God.

That is the church in action. Because we are made in the image of God, that is who we are called to be: a community of love, honoring each other, calling forth the best in each other, joining together in a unity of mission, bound together by the power of the Holy Spirit, unity in diversity, the many coming together as one. We are a Trinitarian community, going forth in mission, and reflecting the love that is the deepest truth and the eternal reality of the heart of God.