Why is British Unitarianism in decline?
So here goes:
First and foremost Unitarianism is in decline because religion in Britain is in decline. For whatever reason (and plenty of people are thinking about this) active adherence to religious institutions has been dropping for a very long time. Immigration reverses this trend in some areas (most church-goers in London are non-white for example). But overall the trend is the same. Brits have rejected religion.
But I don't see this as an entirely bad thing. Many people in the past were religious purely because of social momentum. They did what everyone else did. This doesn't mean it meant that much to them.
For example 60 years ago my church was much bigger. It was an incredibly active place. However, this was largely because the church was the centre of people's social lives. You didn't go to a club on Saturday night, you went to a dance in the church hall. Our old and huge Sunday School building (now demolised) was a place for dances, amateur dramatics, a gymnasium and every kind of social activity. It was where people hung out with their friends. It was where people went on dates.
It's hard to say any of these are bad things. But how much do they have to do with the primary purpose of a church, to create spiritually mature people and build the beloved community? Not a lot. If people's lifestyles mean they don't need to have a social life invested in the church anymore, then fine. Stuff changes.
Secondly Unitarianism is in decline because it is isolated from the Christian community. Please note that I am not saying we are in decline because we're not Christian enough anymore. What I'm saying is that sources of renewal in Christianity have not touched Unitarianism. I've already mentioned immigration. That is having a huge effect on many different denominations, and offering some boosting in terms of numbers and energy.
But not only that but things like charismatic renewal that have had an effect on many churches, not simply Evangelical churches but also even the Catholic church. Charismatic worship, and other worship innovations, new songs, new instruments, new technologies have offered lots of places for renewal in mainstream churches. This has not touched Unitarianism. I'm not giving a value-judgement to that. I'm just saying the fact is a lot of mainstream churches that do this kind of thing are growing, against the trend of denominational decline.
Thirdly Unitarianism is in decline because it has no institutional memory of church planting. Almost of all of our churches existed before Unitarianism. They were independent Protestant dissenting chapels that converted to Unitarianism. So churches for us were things that were always just there. We still have no real concept of how to start a church. It's pretty inconceivable to us.
This is true of most British denominations still. In America as the country expanded to the west you had to plant new churches otherwise there would be no churches where lots of people were living. In Britain, with a parish-christendom mindset we tend to think of churches as eternal things; things that have always been there and always will be there.
But church planting is the most reliable way to grow a denomination.
Fourthly Unitarianism is in decline because we are still producing pastors not missionaries. In ministry training there is an assumption of a maintenance way of doing ministry. Such a way of doing ministry may have worked in the past but today it is likely to produce the result of a declining congregation. Ministry training needs to equip ministers to be missionaries, either in the business of starting up new ministries and congregations, or in the business of managing institutional change to make congregations into missional communities.
Fifthly Unitarianism is in decline because it has no theology of evangelism. We have no understanding of an urgent gospel message. We largely do not accept that the purpose of a religious community is change/metanoia/transformation of people and the world. We do not say, "here is a coherent way of life, a way of being in the world, an ultimate concern that will give your life meaning and purpose." We struggle to answer the question of what difference becoming a Unitarian will make to people's lives.