bounded set and centered set (more alan hirsch)

One idea that comes up in missional church planting is the idea of "bounded set" vs. "centered set" church philosophy. The idea is often credited to social systems theory (not talking about math here), although if you google for it, you'll get more hits on church blogs than anything else. It's buzzy right now, I guess.

First, what's the difference? Bounded set communities seem to describe most churches. Membership in a group is defined by an assent to a shared set of beliefs and behaviors. The mission of members is to ask people to belong by conforming. By contrast centered set thinking defines a group by its center. In this case, placing Jesus at the center, and allowing for the fact that all humans are at various distances from that center. The role of the group becomes to draw people closer to the center, not to define who is in or out.

The problem is, I still can't decide whether it is Biblical or not.

Alan Hirsch's
wife Deb, was presenting this model at the Ecclesia gathering in DC, and asked "which of these in more Biblical?" loudly with the implied answer of "centered-set." It was too simplistic for me.

The centered set is very attractive to me, and fits with my consistent idea that discipleship and evangelism are really very much the same thing - taking people closer to Jesus no matter where they are. And the Graham Tomlin (The Provocative Church) idea that a leader is to "keep the center hot not guard the edges" has rung true for me for years.

Yet don't the sacraments - baptism and the Lord's Supper - have a mandated? role of helping define who is in and out? Committed or not? Don't they provide a boundary marker for who is in the family? (clearly Hirsch wouldn't think so - but he's anti-sacramental on the grounds they de-sacralize all of life. I disagree here).

And as much as Hirsch likes to cite early church example, wasn't the catechical process for training and admitting new believers a long period of time? Three months? As long as a year sometimes? Weren't they not allowed to enter the church proper until the process was complete? Talk about "in and out."

So I'm torn.