A General Model of Church Growth and Decline

ABSTRACT

An earlier model of church growth (Hayward, 1999) is extended to include long-term effects due to births, deaths and reversion from the church. It is proposed that only a subset of the church, the enthusiasts, is involved in the recruitment process, and only for a limited period of time after their conversion. It is found that the church reaches equilibrium in its proportion of society according to the potential of these enthusiasts to reproduce themselves, and the losses from the church. If this reproduction potential is below a threshold that depends on losses, then extinction occurs. If it is above a higher threshold, then the church sees rapid revival growth. The model is applied to a number of church denominations to examine their prospects for survival or revial growth. Generally, declining churches do so because their reproduction potential is inadequate, rather than due to excessive losses.

Keywords:

• church growth
• differential equations
• diffusion
• epidemics
• population models
• religion

Notes

¹In Hayward (1999) τ _a was called D, and C _a was called n _i (t). n _i (0) becomes the conversion potential C _p .