Do you like doing jigsaw puzzles? Some people have one on the go all the time. But of course it is a free country. My granddaughter loves them, though she likes to have a good look at the picture on the box first. She also gets very cross if a piece is missing. God is a puzzle. How do we fit all the bits of the jigsaw together to get a clear picture of what he looks like when there is no picture on the box to look at?

Models are useful things. Back in the Stone Age when I was doing O Level chemistry we had to learn chemical formulae. The diagrams of letters and numbers told us clearly the substance in question was made up. But however accurate a formula H20 for water, or H2SO4 accurate for sulphuric acid might be, they were only models. The reality was something else entirely.

The Trinity is the Christian model for understanding God. We have these pieces of the jigsaw, Father Son and Holy Spirit. Correctly joined they solve the puzzle. Christians believe they make an accurate way of understanding God.

Now Islam and Judaism are adamant that our model is wrong. “Hear O Israel, the Lord your God is one Lord.” “There is one God and Allah is his prophet.” What fun the East London Imam had in teasing the Rev Adam Smallbone about his three Gods: Father Son and Holy Spirit.

But Christians have always found that looking at God as one was never enough. Many years ago St Augustine’s great brain wrestled with all this. Yes God the Father is one. But Jesus clearly seemed in a sense to be God as well. In so many words he told his followers, “See me and you have seen God”. And Jesus dared to use the scared name of God; “I am” about himself, the ultimate blasphemy, and a name so sacred that Jews only referred to it indirectly. And risen from the dead Jesus seemed to have made his claim good.

Then there was this funny business about the Holy Spirit. Nowadays thought Augustine the Spirit seemed to be available everywhere for all humanity, and he seemed to have the all the divine powers we might expect of God. The Spirit was blowing hard through the whole Roman world. What sense could be made of the whole thing?

Augustine gradually came up with the idea of God as one, but made up of three ‘somethings’. For something he used the Latin word ‘persona’, hence three persons one God.

Do you see what I am driving at? The puzzle of God seems in one way quite clear on the box, he is one. But inside he appears to be made up of a jigsaw, all the pieces of which are equally important, hence one God, Father Son and Holy Spirit.

But does it matter? Well yes I believe it does. For Judaism and Islam God is remote and unknowable, a mystery presence to be revered and placated by sacrifice and good works. For Christians God is still ‘transcendent’ to use the jargon, but in encountering the person of Jesus Christ and experiencing the Holy Spirit all at the command of God the Father, the transcendent becomes imminent, the unknowable becomes knowable, the power realised here and now.

This week I will do an assembly on all this for the children at our schools. I have a big piece of card. On one side in big letter it says God. On the other side there are three names, Father Son and Holy Spirit. The card is pre cut into three jigsaw puzzle pieces. I will play around with the model, take it to bits, show the pieces, fit them together, show each side and talk about it and see if it makes any sense. It does to me. I wonder if it does to you? This way the unknowable God becomes knowable, which is a Christian distinctive. Maybe in these days of Trojan horses that is quite important.