Eugene Hor
comments on a trend in the US to move to smaller churches as part of becoming more engaged in the mission of God. It makes sense, and fits with something I've thought for a long time. Years ago when I did chemistry I learned that one of the key variables which increases the rate of reaction is the surface area. So if a solid is reacting with a liquid it will all happen faster if the solid is broken up into a powder than if it sits in a single lump. In ministry it is often better to have a lot of little things happening than having it all happen at one place.

It is a common claim (which I assume is right) that churches are most likely to be in effective contact with their communities when they are a new church plant. So constantly spinning off new churches can keep evangelistic momentum. Also in a smaller church it is more likely that more people will be called on to use their gifts and people are more likely to be in the kind of person to person relationships in which they will care for each other and mature together. (Of course it is only 'more likely' a small church can be just as unhealthy as a large one, and being small can be a symptom of being unhealthy).
Increasing surface area for ministry can be a challenge. A church of 70 adults might manage to support a pastor and have a few good musos and a small children's ministry and see a few people becoming Christians each year. It can be a lot more exciting to go to a church of 700+ with several specialised staff and great music team and cradle to the grave programs that meet all your "needs". More exciting, but it is unlikely that you will get ten times more "ministry" happening, though there might be hundred times more "buzz". Being a pastor for a smaller church doesn't feed the ego as well as leading a big church. Lots of small churches can be harder for a denomination to "control" and service. So there are lots of reasons why we might think bigger is better, but I suspect it isn't so.
I would also add that "spinning off" new churches has to be done with genuine mission motivation. It can not be simply a way to move off a group of people who don't quite fit the "sending church". That will do no good for the sending church nor the new church and will simply show our lovelessness. So I am not suggesting "homogenity" as the main feature of new small churches.
Of course there can be a "critical mass" needed (though that changes the metaphor to nuclear fission!). Churches working deliberately working together can provide that.
Missional chemistry is a reason to keep starting new churches, with the aim of keeping them small. It is a Kingdom strategy, not an empire one.
It might seem strange in denomination of mainly small churches to bother making this case. However I think that the PCNSW often longs to have big churches, while letting our smaller churches feel a bit second rate. It's time to help smaller churches see that they can be right in the middle of mission.