The British Social Attitudes Survey has just revealed that two-thirds of adults, and notably more than half of Christians, in the UK believe 'there is nothing wrong with same-sex relationships'. We have also recently learned that Germany is likely to allow same-sex marriage. These demonstrate the significant change in attitudes in most western countries over the past 30 years – in 1987 only 11 per cent of adults and 8 per cent of Christians took the same view.

Is this inexorable social trend to be welcomed or challenged?

Christians are often urged to be 'in society but not of it'. Certainly we should not conform to the world as if we were the popular press. But we also can't ignore profound changes to views of human nature, of society, and of our world that have developed from science, travel and communication. So how do we judge a 'good' social trend from a 'bad' one? When should we lead society, when follow, and when 'walk in parallel'?

There are indeed 'bad' social trends – such as obsession with wealth, celebrity and appearance, gambling and alcoholism, and individualism with its emphasis on rights rather than responsibilities. There are some largely harmless trends in fashion and opinion. But some trends reflect a wider or deeper understanding of our human nature, the inter-connection of society, or the way the world works. Science, knowledge and education have helped abolish old prejudices that devalued black people, poor people, women, children and those with disabilities or mental illness, and we must celebrate these changes. Christians should sometimes lead, as they did for slavery, but we must sometimes humbly follow where others have already led. Jesus notably challenged his society in attitudes to women and the excluded.

Gender is now understood to be much more complex than we once believed. Whilst most of us seem to fit a simple 'model' rather well, namely of 'men doing manly things', and 'women doing womanly things', many fit less well and some scarcely at all. Fortunately we now generally accept that women can be educated and be in charge, and may be braver and stronger than some men, whilst also accepting male nurses and carers. Gender has multiple dimensions, with behaviour, attraction and self-image not always all masculine or all feminine together. And the one per cent or more of intersex births demonstrates that even in physical (sexual) characteristics we don't all fit into regular 'boxes' of male and female. Was this known and understood in biblical times?

Society is evidently on a journey in its attitudes to same-sex relationships, and Christians seem to be on that journey too. The question is whether the Church is also on such a journey, and is this right? Even if the journey is in the 'right' direction, does it follow it must go as far as society? That is, might we accept some of the changing views of human nature and gender, whilst holding back on some of their potential implications? Might we consciously take a distinctively Christian path whilst still moving forwards? There is clearly more than one answer to these questions, and we are unlikely to agree completely, as nothing is fully known to us, only to God.

I recognise that I too am on a personal journey of knowledge, opinions, feelings and beliefs about the complex issue of sexuality. When I was young, homosexuality was unknown to me. Later it became a joke, then strange, then uncomfortable, then tolerable, then partially acceptable. Where am I now? Am I 'pro' or 'anti'? I don't want to be put in a box, and have it assumed that if I am sympathetic, then I must be in favour of every particular. Overall, I am very sympathetic to same-sex relationships where they are a loving commitment of mutual respect (and against heterosexual marriage where it is unequal, uncommitted or unloving), yet I have reservations I am still exploring about some things that others assume are 'part of the package'.

I think it is unhelpful and often insulting to assume of others that they are either 'for' or 'against' something when there may be many shades in between. Different aspects may deserve separate consideration. Not only may we fail to respect others' views, feelings and beliefs, but we may also harden their views in opposition to our own if ours are too rigidly delineated or harshly expressed.

I believe the trend in social attitudes published today is largely a product of greater knowledge and understanding of what it means to be human. But I think it is legitimate to hold opinions about different aspects of this new understanding. I would welcome a fuller acceptance of the validity of same-sex relationships by the Church, but it is right we continue to challenge society's assumptions where they encourage the selfish pursuit of individual interest. A social trend that reflects a greater respect for humans and a better reflection of God's love is a good trend, even if initiated by non-Christians, who may be a prophetic voice to a church that has become hard of hearing.

Dr John Appleby is a lay member of General Synod for Newcastle Diocese and is married to an Anglican priest. He is head of mechanical engineering at Newcastle University, and was a candidate in the recent General Election.