Last week I shared a link on Twitter to an article that explained how big Sunday school classes can harm a church. The article was very well done, but I felt the author left out one important issue with big Sunday school classes. They are often not attractive to new people.
The people who enjoy a big Sunday school class are often the people who have been in the church for years. This class is like a second family to them. In a very large church this may be the primary place where they receive pastoral care. Everyone in the class knows everyone else, and it's like going to a family reunion once a week.
However, new people don't know everyone and do not have the relationships with the people in the class that the long-time class members enjoy. They can feel very much like an outsider who has crashed a family reunion. After a few weeks of trying to join in they abandon the idea and either come to church after Sunday school or go to another church entirely. Because the class is already large it's possible that their absence won't be noticed for weeks, and by then it's too late to get them to return.
The Sunday school can serve as an important outreach arm of the church. While it's primary purpose is to educate and disciple, it can also be used to reach new people who are not attending church services. However, it's important that the adult classes be kept small for it to appeal to new people. You don't want a small Sunday school program; you just want small adult Sunday school classes. This is why it's important to begin new adult classes on a regular basis.
A good rule of thumb is that an adult Sunday school will stop growing after about eighteen months. This means if you want to grow your Sunday school program you need to be adding new adult classes about every eighteen months. This will require a great deal of intentionality on the part of the church leaders.
New leaders and new teachers must be kept in the developmental pipeline so they are ready to lead and teach when you begin a new class. Sunday school budgets should reflect this planned growth. Effective outreach tools must be developed. People must be trained in outreach and hospitality, and prospect lists must be maintained. Follow-up with first-time guests should be a priority of the leadership, and systems should be developed that will make your follow-up more productive.
When I was going to Bible school in the mid-1980s we were taught that one purpose of the Sunday school program was to reach out to the unchurched. I believe it can still be an effective outreach tool if it is used correctly, and that includes keeping the adult classes small enough that new people will feel comfortable and want to return.