Some fellow I've never heard of, Eugene Peterson, wrote a book in 1987 called Working the Angles: The Shape of Pastoral Integrity. My online friend the Bishop of Buckingham, Alan Wilson, quoted the book on his blog, and then my online friend Tim Chesterton posted the same quote on his blog.
I'm not going to post the whole quote - just the part I found particularly striking.
The biblical fact is that there are no successful churches. There are, instead, communities of sinners, gathered before God week after week in towns and villages all over the world. The Holy Spirit gathers them and does his work in them. In these communities of sinners, one of the sinners is called pastor and given a designated responsibility in the community. The pastor’s responsibility is to keep the community attentive to God...
I've said before that statistics only tell you what they tell you and that's all they tell you. Thus statistics about average Sunday attendance or giving by members do tell you something about the vitality of a congregation. But what they're telling isn't always clear. And even when it's clear, it may not be important.
If only we could find some discrete statistical way to quantify the transforming work of the Holy Spirit in the life of a community and in the lives of individuals.