Some Personal Observations
From 1987 to 1995 I was minister of a United Reformed Church in North-West Ipswich which had been twinned with a congregation of the Protestant Church of the Palatinate in a satellite village of Neustadt an der Weinstrasse since 1982. The twinning continues strongly to this day and last year they celebrated the 25th Anniversary.
It was profoundly moving and challenging to live the Fall of the Berlin Wall through the eyes of German friends and fellow-believers, to help them in their attempts to support congregations in East Germany and Kenya, and, speaking personally, to be invited to preach on Volkstrauertag (the German Remembrance Sunday) in 1991. The strength of the twinning owed a huge debt to the efforts of my predecessor and her German colleague to link the right hosts with the right guests in the initial visits. This led to the development of deep friendships which helped cement and sustain things in the inevitable ups and downs over the years. The presence of two or three bilingual folk in each congregation also helped, as did preparing worship far enough in advance for everything to be translated. It seemed to go so much better when everyone knew what was going on.
The downsides were the inability to sustain the link with East Germany (long story), the occasional lack of mesh between a state church and a (sometimes quite militantly) nonconformist one, and one or two host-and-guest pairings which just did not work!! But taken for all in all the twinning remains something which has enriched the Christian experience of the two congregations concerned to an amazing degree, for which I am thankful to God.
I think the first thing to stress is the need for openness and courtesy. I well remember a case just over ten years ago, when we were surprised to find something like thirty or so French people at Sunday Mass. They had been invited by a nearby Anglican parish and their arrival on our doorstep was the first we knew of the twinning arrangement. The best practice model here, I believe, is that involving the Catholic Diocese of Brugge, the Anglican Diocese of Lincoln and the Catholic Diocese of Nottingham. Wherever possible, efforts should be made to involve the local Church corresponding to the Continental one being twinned with.