A couple of weeks ago I was given a very remarkable present. It came in a small envelope; inside was a small piece of cement mortar and a note, which said: 'I can vouch for the authenticity of this. I took it myself from the Berlin wall in 1989.' It is a present which I will treasure, symbolic of an extraordinary moment in contemporary European history.

In the 1980s, Jan and I had a holiday in Schleswig-Holstein, partly because we had both vaguely remembered history lessons about the Schleswig-Holstein question and wanted to see the place about which the question had been posed. Whilst we were there, not far from Travemunde, we saw a river and beyond the river a fence - the 'Iron Curtain', East Germany. This summer we went again to Germany and went across (even my very choice of words gives me away) to East Germany. No wall, of course, now but places are still struggling to recover. In spite of all the investment (a banker with the German Federal Bank told us that 85 billion euros are being invested each year from west to east), the infrastructure was struggling: pot-holed pavements, broken-down factories, litter blowing around the streets.

But it was in a particularly beautiful town in East Germany, called Quedlingburg, that we chanced upon a tiny Romanesque church. It had a crypt dedicated to St Wiperti – never heard of him? He was a companion of Boniface, from Crediton in Devon, who had gone on a missionary journey to Frisia and Saxony to tell the locals about Christ. This was in the eighth century.

Well, since the holidays I have been reading a fascinating book about the Berlin wall, written by a young German author, Oliver August. He travelled along the line of the old Iron Curtain from north to south, 800 miles from the Baltic to the Czech border – and, as a young German, writes of his impressions. The observation is acute and compassionate, the writing both lilting and incisive. At one point he visits a travel agent, trying to discover what East Germans did when the wall came down:

There was an insatiable appetite for Spain, Italy and France … England was unpopular because people were sick of queuing … some were intensely miserable when they left their protected East German cocoon for the unbridled razzmatazz of the Costa del Sol; other Ossis travelled obsessively to overcome what some called 'Mauerkrankheit' – wall sickness.

[Oliver August, O: Along the Wall and Watchtowers: a Journey Down Germany's Divide,

Harper Collins, 1999, pp.73-74]

The author, Oliver August, obviously longs to understand – and is at times perplexed or frightened, and sometimes amused by what he discovers. It's an easy read, but also very troubling – a book that will stay with me for a very long time. Meanwhile, that little piece of Berlin wall continues to look at me …

Well, I have walls on my mind. And so, unsurprisingly, I turned to Robert Frost's poem called, simply, 'Mending Wall', with its famous opening line:

Something there is that doesn't love a wall.

[Robert Frost: Selected Poems, Penguin, 1955, p.33]

It's a parable about what walls may be for and challenges the proverb, 'good fences make good neighbours'.

I say all of this because I have a feeling that during the life of this Synod, walls might dominate our thinking. I don't mean the walls of our churches – though they might, because one of the major issues we shall all face is how we develop the use of our church buildings. I think, for example, of Hexton and an amazingly feisty project in which a church is being developed not only for worship but also for use by the village school and by the community. I think of Moggerhanger, where the church houses the village shop – and it is also a place of worship. I think of all those 411 church buildings around our diocese whose walls echo with prayer and worship – but where upkeep can be very daunting. One of the questions we shall face, as a Synod, will be not only how the church walls can contain places set apart for God but also how they can be used imaginatively without destroying their central purpose.

Then there is another wall: the wall marked 'Christian Unity'. Some of us have been trying to create doors and windows in fortress churches all our lives to let in some light – and during this Synod we shall have to work even harder to see how not only physical structures may be better shared by fellow Christians but also ask whether some of the walls that still separate us have any twenty-first-century purpose, or whether they aren't, like the walls of Verulamium, interesting and important bits of history, but no longer serve their original purpose.

And the third wall is one marked by a sign 'Children and Youth'. The metaphor is about to be pushed to breaking point – but as I travel around the diocese, I see some fascinating work with children and young people where the walls of the church, as it were, are both a proper place of safety and also a climbing wall. But, frankly, in some of our parishes the walls of the church simply do not echo any longer to the cries of children – either cries of despair or cries of joy. I do not want to heap blame or guilt on us, but a godly wall which, as it were, embraced and encompassed children and young people, with plenty of exits and entrances, is desperately needed.

And finally, there are already walls of our own making. Think of these as movable walls constructed not outside, but inside our churches; these walls are under constant pressure and are pockmarked with labels. Each label signifies a subset: Evangelical; Liberal; Catholic. Let me remind you – these walls are inside our churches. And we repair them and man them, and sing our own tribal songs loudly inside them – and think that by so doing we are going to be heard. We confuse loudness of noise (volume) with effectiveness, and don't realise that what we think of as rousing tribal songs are heard outside as muffled and incoherent squabbles. Those walls may be fun to be within and they may provide some necessary shelter from time to time, but they do not have any serious functional purpose in relation to our need to share our faith with others. They echo loudly, but only to the sounds of our own voices.

It's those internal walls we need to gently dismantle so that together we can face outwards in God's strength t to His world.

I suppose what I am saying is that as a synod we shall have to decide which walls serve a proper and necessary purpose (good fences do, indeed, make good neighbours) and which walls are divisive and need to be moved or dismantled altogether. Our faith requires both – whilst our Lord was crucified and rose from the dead outside the walls of the city, the dream of the End Time in the Book of Revelation is about entering a holy and most beautiful city, through gates made of entrancing jewels – and at the centre of the walled city is God.

I invite you to join me in a bit of wall demolition and a bit of wall building in the years ahead. We shall have to listen very carefully to hear where the sound is of Christ wielding a sledgehammer and where it is the sound of Christ wielding trowel and mortar – and then do as He, the master builder, would have us do.