I'd like to quote Bonhoeffer from Alan Knox's blog:

The Church is the Church only when it exists for others. To make a start, it would give away all its property to those in need. The clergy must live solely on the free-will offerings of their congregations, or possibly engage in some secular calling. The Church must share in the secular problems of ordinary human life, not dominating, but helping and serving. It must tell men of every calling what it means to live for Christ, to exist for others.

It's well worth looking at the full blogpost. I can see a few things I'd adjust slightly but the heart behind this is undeniable in it's call for authenticity in the way we are church to those who are not.