What Predicts Church Growth or Decline?

How a social scientist thinks about religious change

I am, at my core, an empiricist. This worldview contends that human beings gain knowledge exclusively through experiences derived from our five senses. When I talk to my political science graduate students about this, I tell them simply: we have to base our arguments on facts and data. We aren’t pundits. Our work should transcend personal opinions. When you think about the term political science - you should put a whole lot more emphasis on the word “science” and a whole lot less on the word “political.”

The first reading that I have them study in research methods is the classic textbook by Nachmias and Nachmias. I am especially fond of a section in the first chapter with the heading - Basic Assumptions of Science. I have internalized their list to an extreme degree. Let me describe a few of these assumptions.

1. Nature is orderly. There is a pattern to how things transpire in the natural world. Events do not occur randomly.

2. We can know nature. Human beings are a part of nature and we can understand human nature just like botanists understand the krebs cycle. If we can’t then, what’s the point in this entire endeavor?

3. All natural phenomenon have natural causes. This one is the most germane to the discussion. From an empirical perspective - there has to be a NATURAL cause for a phenomenon. That cause CANNOT be supernatural.

This obviously puts any empirical scholar of religion in a tough spot. It’s happened to me several times over the last few years. Someone will be telling me about how the church they attend is just growing rapidly - adding new members every single Sunday. They are hiring new staff. Raising funds for a new building. Establishing new ministries. I listen for a bit and then ask them a simple question, “Why do you think that your church is growing?”

The most common response is, “Well, we have been praying for revival for the last few years. Our pastor just preaches the Bible and God is blessing our faithfulness.” My empirical brain hears that and says simply in response, “That cannot be the answer, because that violates every assumption that I have about how the world works.”

I can model lots of things. I cannot model the Holy Spirit. It just doesn’t work like that. And this makes a certain type of religious person very upset with me. It’s often those who are members of very charismatic churches who spend a lot of time talking about supernatural things.

When I think about why churches are growing or dying, my mind immediately goes to natural explanations. I need to be able to use data to understand the world around me. So, I did that back in 2021. I scraped Outreach Magazine’s list of the fastest growing churches in the United States.

You can learn a whole lot about a church by looking at one simple thing: their location.

I had my graduate assistant look up the address of each of the 155 churches on that list. Then I had her compile some very basic demographic information about all of those churches. These results make my empirical heart sing.