“Groups are how we connect here. Groups are how we care for people, grow people, and involve people in ministry and mission. If you don’t join a group, you will never really be one of us.”
~ Len Hjalmarson from Small Groups - Cell Church
That last sentence can sound a little harsh and exclusive but I really don't think it's anything other than the cold hard truth about the way(s) in which humans connect and "actually" care for one another. Life together is work, and it isn't as easy as we often expect it should be.
Taking this thinking a little further I woud suggest that some amount of exclusivity is necessary to foster a truly inclusive environment where people connect and care for one another; having to break down some sort of barrier to begin with paves the road to come so to speak (perhaps this is where rites of passage and initiation ceremonies have worked so well in creating group cohesion over the centuries).
All this to ask: if our effort to join the community prepares us for the effort it will take to maintain it, how do we create a welcoming community which doesn't shy away from asking more of those who wish to join it?
Furthermore: how do we develop such rites of passage without at the same time contributing to a view of the world which draws hate-fueled lines between "us" and "them?"