When I was invited to speak, I began by enumerating the points I wanted to make. I have learnt that this makes it harder for a presenter to cut me off before I have made all the comments that I plan to!
My first point was to note that our current approach in society is a novelty, and is the result of some fundamental changes in the way we think about our bodies, sex, and relationships. I have noticed that the debate often starts with the assumption that belief in same-sex marriage is obvious, natural, and is the final end goal for our thinking about relationships. A little bit of cultural and historical awareness, though, shows that, in comparison with most cultures in most of history, we are very odd; I also want to point out that we have faced very rapid changes in attitudes, and changes are likely to continue in one direction or another. I noticed that Andrew nodded his agreement on this point.
My second point was that the C of E is rooted in the 1662 BCP and the 39 Articles; if we are to change our doctrine of marriage then we will need to redefine the C of E. I went on to make the point I have made previously in various places, that there is a strong consensus of what the Bible says, and to introduce change we do (as Francis Spufford does with honesty) need simply to say that, on this, the Bible is wrong. Andrew seemed to agree with the first of these two, but shook his head on the second.
Read it all and please do watch the debate via the links provided.