More often than not, we simply count heads. Usually this means that we're essentially counting how many people are in the same room together. The problem with counting heads is that it hardly gets at missional progress. For instance, what if a new church plant gathers a thousand people BUT nine hundred and ninety-five of them are transfers from other churches? Yes, this may be nuanced, and perhaps hundreds of people in the area were going to drop out of many of the local churches anyway? But in general, it is likely the least effective metric we might apply. Simply counting heads is hardly the most responsible metric for assessing missionary progress.
When I was doing my doctoral research, I interviewed a handful of leaders who were planting "house churches." A house church or small group is going to have a low number of people in a room together. However, I asked them about their ratio or percentage of new believers or lost people vs. already believers in their church planting effort. 8 out of 10 estimated they had more than fifty percent new believers or lost people. These sort of communities largely fly "under the radar" because of their small size, but their impact may be significant. BUT only when we reconsider applying a different metric.
IF we want to use counting for discerning our stewardship, determining the ratio of lost people & new believers to already believers who join the ministry may be far more helpful to clarify missionary impact. However, I do think there are also other (non-numerical) metrics that may help us evaluate our use of resources. Another metric is listening to stories of transformation. We may shy away from this because this approach doesn't fit on a spreadsheet, but if we hear a steady stream of stories of lives changed (or changing) as a result of the Gospel, this may represent a significant impact for God's Kingdom.
One of the metrics that I've been applying to my own ministry is asking whether "indigenous" believers are reproducing ministry. It's difficult to put this on a spreadsheet as well, but I often ask this question self-critically. Are new (or restored) believers reproducing compassionate service and evangelism among their relationships? For me, this evaluation determines whether something truly lives beyond my immediate influence. Evaluating my own ministry impact on this basis has also helped to refine & refocus my ministry to work towards this outcome. It's not hard to find ourselves serving people for long periods of time who only passively receive our services, so focusing on reproduction has helped me to make changes and adjust my primary focus as I serve others.
We could continue to list possible metrics that demonstrate a greater faithfulness to our calling, but the greatest one of all is just that -- faithfulness. Some sow, and sometimes others reap. I'm thankful that in many of the hot spots for church growth around the world today, there were first missionaries who labored to cultivate the soil through decades of faithful service in (then) resistant fields. Just as many missionaries laid the foundations for movements decades after them in Africa or China, similar cultivating work needs to be conducted in Post-Christendom Europe and North America.
Applying metrics to the missionary endeavor is a reality, and applying metrics to missionary service is often rooted in good intentions -- in values of stewardship and mutual responsibility. However, if we are to be honest, we haven't always done well in this regard. There is a problem with our metrics, but we may find that applying a different metric changes our whole perspective.
-Jared Looney (New York City)