I believe that as a movement, the mega-church movement is doing positive harm to the cause of Christ. Harm, not because churches are large, but because of the consumerist spin placed upon the Gospel which cannot sustain Christians to stand in the face of trial. The human-centered focus results in a pietism that is antithetical to the Gospel. So I also believe that this pietistic mindset is the cause of the call to retreat from fully engaging the culture. Preliminary research sources and theses here.