If you have ever been a pastor in a really small town, you will know what I am talking about.
You can be in a tiny town and see churches that haven’t really grown in years. They service a few families and that is it.
And then the suburbs grow to encompass the town and everything changes. New stores. New gas stations. New traffic lights. And of course the real challenge: new people.
And so many churches start to grow. New people, new children in Sunday school, new officers, new Bible studies and outreach projects, new building programs eventually.
But sometimes a church remains the same in the midst of all this growth. Same people and same families. Same size.
Because if it doesn’t grow eventually the more productive people who aren’t directly tied to the main family (and there always is one) will decide they want a more open community.
And as the church remains the same and then shrinks, there will be a flurry of sociological and theological rationalizations. We are a loving community but others don’t want commitment. We are theologically astute but they are all Arminian or liberal or don’t recognize that our unused copy of an ancient creedal statement was the pinnacle of human history and doctrinal development.
And amillennialism will also help. God loves a remnant for its own sake, not as a seed for growth.
This happens in small towns (when there is economic growth, anyway) all the time. The church becomes older, grayer, and not any wiser.
But what is true of churches in small towns will also prove true of ingrown denominations on planet Earth. The growth of Christianity means some entire communions will sink into oblivion with no one but some church historian who is later searching for an excuse for a PhD dissertation to document the groups decline for postmillennialism to amillennialism.