Rachel Held Evans answer seems to be attracting attention for some reason. Here are my first thoughts on an answer, for what it's worth...
Declining church membership is a Spiritual and not a sociological or marketing problem. It requires a Spiritual and not a sociological or marketing solution.
Everyone is an individual, but you could follow Jesus and break down the reasons into three categories:
- Some people are hardened to the Gospel for a variety of reasons. They won't even take the time to think about the Gospel because the Devil snatches it out of their mind.
- Some people get let the Gospel get crowded out by other concerns in their busy lives. Earning and spending money consume whole lives - literally.
- Some people are afraid of the cost of following Jesus, especially the cost in their relationships to family, friends and colleagues.
My guess is that there is good reason to think that the later two have been particularly on the increase over the last few decades. I'm not sure whether the first is improving or not.
- Preach the Gospel more - there will be no fruit without good seeds
- Recommend the Gospel more - by changed lives of love
- Pray for good soil more - because only God can change hearts.
- Send out more workers into the harvest - because the God uses people.
Simple, but not easy! Help us Lord!