Yesterday I did a radio interview about the release of our new book, Small is Big! Unleashing the big impact of intentionally small churches. (It's a paperback version of The Rabbit and the Elephant with new and updated material.) The interviewer asked a question we find frequently comes up with people new to the concept.
"What about heresy in the house church? When there isn't a well-trained pastor, isn't a small group liable to go off the rails?"
Here's the gist of my answer to him:
Where does heresy come from? If you study the history of heresy, it most frequently starts at the top of an organization. The head of a denomination or a seminary or megachurch teaches something off the wall, and the people follow. Renewal, on the other hand, tends to be a grass-roots movement. The lack of hierarchy within the simple church movement is a safety. Besides that, even if a simple/organic church does acquire some wrong doctrine, it is unlikely to have any impact beyond that group.
Where does our authority lie? When teaching occurs from the front, the authority lies in the teacher. When all of us study from the Scripture (as usually happens in a simple/organic church), the authority is in the Word itself. This is especially true when whoever is facilitating (or is well trained in the Word) doesn't answer people's questions, but points them back to the Word for answers. When everybody is trained to study the Bible for themselves, they will quickly pick up on weird doctrine.
The Holy Spirit leads us into all truth. We have frequently seen this in action. For example, in a church we helped to start in low-income housing projects where the average reading level was around 2nd grade, I was frequently amazed at how often I heard people quoting Scriptural concepts. They had picked them up from the passages we studied together, but they were applying the principles to other situations.