The wall is the thing which separates them but it is also their means of communication. It is the same with us and God.
Every separation is a link.
A journey for you - If you visit the Welsh seaside town of Aberystwyth, you can travel inland to a place called Strata Florida, ancient ruins of what was once a Christian Abbey. And a bit further on down the road, you will come to an old manor house by the name of Nanteos. It is there - you can make up your own mind. The story told is that when Joseph of Arimathea came to Britian it was the good monks at Strata Florida that put him up - and it was these same good monks who later hid the grail at Nanteos. It is now just a shard of wood, barely a cup, but the family at Nanteos claims it is the real article.