When is it a church?

My latest article for Geneva:

If the church is found wherever two or three gather around Christ, why not call growth group church? Why not call family devotion church? Why not call the AFES ministry church?

Some people might quite like the idea of that. But it has some grave problems:

Are Christians members of multiple churches all at once? Do you appoint elders to each of these groups? Do restrictions about gender roles apply to each gathering equally? What about 1 Corinthians 14:35 that creates a distinction between speaking in church and at home? Besides, in practice even the radicals have a defined group of people they consider to be a distinct church.