Trinity Sunday! The day preachers try to avoid preaching because how do you explain the Trinity? I gave it my best shot – and here it is! I wasn’t preaching at home this week – I was away at St Mary’s Church in Caterham, our next door neighbour.

Isaiah 40.12-17, 27-end; 2 Corinthians 13.11-end; Matthew 28.16-end

Don’t you just love parish quiz nights?

In my last parish, at one quiz night, there was a round just for the clergy. The person who had set the questions seemed determined to catch the clergy out. So, he asked a question: what was the name of the prophet Isaiah’s second son, who has the longest name in the Bible?

Of course, you all know the answer! At any rate, the clergy responded without hesitation – Maher-Shalal-Hash-Baz. The questioner was so disappointed we knew the answer!

It’s the St Mary’s Quiz Night. And up comes the question. How many persons in the Trinity?

Well – you’ve all been really good and paid attention to all those sermons on Trinity Sunday over the years – so you know the answer. Or at least, I hope you do! But before we come to the answer let me tell you a story. It’s not my own story, it’s a story from Donagh O’Shea, an Irish member of the Dominican Order.

I want to pass on to you (he says) an insight I received years ago in a small church in Rome: the preacher was a tiny vivid Italian with flashing eyes, and a chasuble and gestures that were both far too big for him. He was preaching in a church beside the Tiber, on Trinity Sunday. He told of his earlier years in a parish near Naples. In those days, he said, the days of his youthful enthusiasm, he had begun to wonder if the people in his country parish remembered anything of Christian doctrine. They were good people, he said, but he wondered how much they knew of the faith. There was only one way to find out: he had to ask them.

So he would ask them, out of the blue, in the middle of a conversation or when he met one on the road: “Franco, how many Sacraments are there?” or “Cristina, tell me, what are the precepts of the Church?”

One day, he said, he was talking with Gianni, a very poor farmer with a large family and hard put to it to feed them. “By the way, Gianni,” he said, “can you tell me how many persons there are in the Trinity?” 

“Persons in the Trinity!” said Gianni with amazement; “l don’t know. Four, five, ten? I don’t know, and I don’t care. I don’t have to feed them!”

Doctrine! Don’t worry. Unlike the priest in the story I promise that I won’t ask you as you leave questions to see what you know about any particular doctrine. Now, there is only one Sunday in the whole of the Church Year that is formally dedicated to a doctrine, and that is Trinity Sunday. And that’s probably a good thing –- because if there’s a way to make sure that people don’t listen to your sermon it’s to preach on a doctrine. But today I have little choice, so here goes!

I began with a question, and I’m sure that even if, like Gianni in the story, you didn’t know the answer you’ve worked out by now that the answer to the question I began with is three. And yet … we believe in one God. That’s how the creed begins.

Today is Trinity Sunday and our readings remind us of the nature of the Three-in-One God – Father, Son and Holy Spirit – who created and is at work in our world and in us. In our Old Testament reading from the book of Isaiah we hear the writer telling us of the greatness of God. He reminds us that God is the creator of the whole earth. And yet a God who reaches down and supports those who wait upon him. Sometimes, perhaps, it seems impossible to truly grasp what God is really like – he is just too big for our finite minds to get around: his understanding is unsearchable says the writer, and yet he cares for us.

Our gospel reading this morning comes right from the very end of Matthew’s gospel. And it states in quite unequivocal terms a developing doctrine of the Trinity. Sometimes theologians say that the doctrine of the Trinity isn’t explicit in the New Testament. But this is one of those places where you can’t miss it.

The eleven have their last meeting with Jesus as Matthew describes it. And he says to them: Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit …

We immediately recognise that as a Trinitarian formula, used by the Church since its earliest days. We begin our service with those words: In the name of the Father and of the Son and of the Holy Spirit.

But try and think yourself back into the minds of the eleven when they heard Jesus say this. And the minds of those who first heard Matthew’s gospel read to them. The eleven were all Jewish, We know that Matthew wrote his gospel for a Jewish community. And they would have had an immediate understanding of what Jesus meant by the Father and by the Holy Spirit. The Father was God – Jesus had taught them to call God their Father when they prayed. And in Jewish understanding of the Scriptures whenever the Spirit of God was mentioned they knew that was a particular manifestation of God. The Spirit of God had moved over the waters in creation – the second verse of Genesis tells us that – yet they knew that the Spirit of God wasn’t different from God, but was God himself, was God acting in a particular way.

And then Jesus goes and puts himself in the middle – right between the Father and the Holy Spirit. And you can’t give a clearer message than that – Jesus is saying very clearly to the disciples that like the Father and like the Holy Spirit he is God and a part of the Godhead. One God, but manifested in different ways.

And as time passed after the resurrection the disciples slowly began to understand that Jesus and the Holy Spirit and the Father were but different facets of the One God who created everything – Father, Son and Holy Spirit, yet still distinct, each from the other, in some way. But also still just the one God. And we see that growing understanding in the threefold blessing that Saint Paul gives at the end of the 2nd letter to the Corinthians, our New Testament reading for today. The special prayer that we call The Grace.

And today on Trinity Sunday we try to grasp that there are three persons in the Trinity – and yet one God. Perhaps that’s too abstract a concept for mere mortals to get their minds round. We experience the God who created us, the God who redeemed us, and the God who lives in us day by day. And yet trying to explain the doctrine of the Trinity, the God who is one God, and yet three distinct persons is so difficult It’s no wonder that preachers dread preaching on Trinity Sunday. Saint Patrick famously used a three-leafed clover as an illustration. The Orthodox Church very helpfully says it can’t be explained but that it’s a mystery – and there’s no point in trying to explain it rationally.

Well – if you go away today and remember just one thing remember this. In each of our three readings today we are told that God reaches out and embraces us, God wants to be with us – but that his presence with us is in response to our desire to be with him, to reach out to him, to live his ways and according to his commandments.  It’s a two-way relationship.

Isaiah says: Those who wait for the Lord shall renew their strength. Not everyone, but those who wait for the Lord.

Paul says: Put things in order … agree with one another, live in peace; and the God of love and peace will be with you. Sort your lives out, get your community in order – and then God will be with you.

And Jesus says, only after his instruction to baptize and to teach obedience to his commandments: I am with you always, to the end of the age.

I’m going to finish with a prayer written especially for Trinity Sunday by The Children’s Society, that expresses that link between our desire to reach out to our great Three-in-one God, and God’s desire to reach out and love us:

God, our Eternal Parent and Creator, in whom we know of greatness, majesty, strength and might.
God the Son, the Beloved Redeemer, in whom we know of love, self-giving, forgiveness and eternal embrace.
God the Holy Spirit, the Breath of Life through whom we are bestowed with gifts and peace, and gentleness.

Holy Trinity, surround us with your dynamic love.
One in Three and Three in One, teach us to be one.
Unite us all in loving relationship, young and old,
that we may open to receive, ready to give, and at ease to serve. Amen.