Recently, I had an opportunity to take a seminar under Dr. JD Payne at The Southern Baptist Theological Seminary in Louisville, Ky. He has a book out on Missional House Churches, which essentially studies what by one definition would be successful house church groups. On his blog, he recently posted a link to some major news articles on their movement. Here is a link. Here is another. The goal of Dr. Payne's book is to isolate a certain kind of church: house churches. Furthermore, he wants to find ones which are growing in a healthy way and see what they are doing right, and Scripturally. This in turn would benefit those in the house church movements with ways to improve their ministry. Payne provides some helpful advice for change in those movements, including better supports of missions and associational work. He endorses having pastors (whereas most house church people seem anti-pastor (though they would predictably deny this claim)). My main goal is not to endorse house churches here. Personally I am more of a regular (i.e. read 'weekly') both corporate and small group balance type of leader. The large and small settings go hand in hand to match the NT model. While some house churches come together or associate, many honestly do not. This is a weakness as the New Testament presents both elements, the large gathering and the small intimate one (Acts 2). Both represent church ministry.
What I do want to bring out is the element of community that is genuine, rather than sterile and boring like a classroom. The home setting / apartment setting that these gatherings offer is stellar, in that with less than 15 or so believers, much real ministry (real accountability more than a typical Sunday morning, 'how are you doing?') can take place. This is just how people are, they open up in a smaller setting, to encouragement, admonishment, helps, etc. Moreover, those who are reticient to join a larger group at first, or who would not open up in a larger group about a sin struggle; may do just that in a setting with people they know. This is a huge doorway for the church to evangelize and to see the gospel break into lives it would otherwise not meaningfully touch. When people speak truth into each other's lives at that level ( open up in a gathering of ideally 12 or less), they gain much more spiritual strength to fulfill OT models and wisdom, and NT commands to grow in just that manner. Iron sharpens iron. This does not only happen between individuals in a smaller setting (it could in theory happen in an impersonal larger setting off to the side or among friends after 'church'), but without a smaller setting it is a near certain fact that not much spiritual maturity will be added to Christian believers. In light of this, there is a lesson from that movement: smaller settings of 12 or less are also part of the church. Persons will grow in greater Christlikeness as they are related to in that way, bringing the Word of God to bear in each other's lives.