I'm about halfway through Dave Browning's brand new book, Deliberate Simplicity: How the Church Does More by Doing Less (Grand Rapids: Zondervan, 2009). He makes some great points about our need to continually reform our practice in order to bring it in closer alignment with the teaching of the New Testament. He quotes Chesterton in this regard...
All conservatism is based upon the idea that if you leave things alone you leave them as they are. But you do not. If you leave a thing alone you leave it to a torrent of change. If you leave a white fence post alone it will soon be a black post. If you want it to be white you must always be painting it again; that is, you must be always having a revolution. Briefly, if you want the old white post you must have a new white post.
Complacency is deadly in ministry, for - as Chesterton notes - when we leave things alone, we subject them to a torrent of change. It seems there's a ministerial law of entropy continually at work, ensuring that deterioration will follow from stagnancy. Thus, we must take up the cry of the Reformers, and be always reforming (i.e. semper reformanda). Of course, this is not reformation for the sake of reformation. The goal is to think in new ways to get back to old ways; to think of the future in terms of the past. I think our natural tendency is to stray from the New Testament model of church, since the NT picture is...well... brutally challenging.
I get downright giddy thinking about the impact we could have if we prayed relentlessly about how to best live out Christ's commission (Mt 28:19-20), and if we were willing to make tough changes to see it fulfilled.