There is a business theory that says the more sales points, the more the sales. If you build more retail outlets you will move more product.

This is the case with McDonalds restaurants and banks. But it didn't work for Krispy Kreme Donuts and Starbucks. So is it true that if we plant more churches or congregations and have more ministers on the ground we will grow the gospel?

As one of the ways of exploring how we may reach our city with the gospel I have been examining how epidemics take hold.

It has been interesting to find that in church plants outside Sydney, in areas where the community is regularly refreshed and changing, where there are few gospel proclaiming churches, the growth of church plants fits very well with models of how epidemics spread. By way of contrast the epidemic models hardly ever fits the church plants that I have investigated in Sydney.

I have no definitive answers yet as to why this is the case, but it does seem that there is some vaccination or inoculation against the gospel has occurred in Sydney.

While I have no data or analysis yet to back up the reasons why this may be case here are some thoughts about what has caused this vaccination.

1. We are not good at infecting those who have a predisposition to viral infection with the gospel. Epidemics take off when a community have a predisposition to infection. I wonder whether we have people who come through our church doors and so are open to being profoundly influenced by the gospel but we are not good at keeping hold of those who visit. We keep seeking those who never visit, and these are less inclined to be infected with the gospel.

2. Viruses require contact between people in order to be transmitted. Could it be that in Sydney we are not good at contact? It may be that life is busy and cluttered so that contact is only fleeting? Maybe we have so narrowed down the way we live life that we have fewer connecting opportunities than in regional areas.

3. For viruses to become epidemics an ever increasing number of possible subjects are required. Much of the way we engage in ministry is to focus hard on those we have. This is absolutely right and Christian, but those we focus upon need to take the truth that has affected them into new areas.

4. Epidemics require sites that have a large number of people flow through them. Our main gatherings occur in church buildings that take people out of mainstream contact. I am surprised that so many people in our community assume church buildings are not used because they are occupied when they don't see it.

5. Could it be that we have a weak strain of the virus? Cities have a habit of drawing people who are on the way to something. They live in the city to achieve a goal. Affluence, success and fame can easily undermine the desire to live in the city to see Christ's name glorified.