We need to be reminded frequently of the role of the Holy Spirit in bringing about renewal in the church. I distinctly remember a pivotal moment in a D-Min class on Missions and Ministries after we had jointly studied numerous renewal/revival movements in Christian history, seeking some sort of commonalty.
Essentially, we were looking for a way to engineer the movement of the Holy Spirit. After much study, reading, and discussion, we came to the conclusion that we don't get to demand that the Holy Spirit show up on our time schedule. Like the wind, the Spirit will blow as the Spirit wishes.
All the techniques in the world (even the five basic practices!), even applied perfectly, may lead to an institution where the numbers look great, and the pats on the back come with admiration, perhaps mingled with some jealousy for such accomplishment, but those techniques do not mean that real holiness is present and real transformation is taking place.
I also learned that most, if not all, of those movements were indeed grassroots movements and most, if not all, very much upset the established religious authorities. If a real renewal movement were to show up in the UMC, we would come out on the other end very upside down. How many, especially those with seats of power, authority, and comfort around them, really want that?