church membership?

There has to be some sort of mutual "membership-ish" understanding in the background of 1 Corinthians or else Paul couldn't tell them to "expel the immoral brother" [5.13].

So, what should church membership look like today? Did the Corinthians make each other sign a church covenant? How did they have a mutual and clear understanding of local church unity? It was there somehow.

Here are a few different church membership vows or church covenants that I've been reading over. Some are really incredible. I looked at Joel Osteen's church. Couldn't find one?

• The Village Church, Matt Chandler... here.
• Bethlehem Baptist, Dr John Piper... here.
• Mars Hill Bible Church, Rob Bell... here.
• Mars Hill Church, Mark Driscoll... here.

The straightforward membership summary of Mars Hill Bible Church is really beautiful:

BACKWARD, embracing the roots of our faith.
FORWARD, because the life of faith is a journey.
INWARD, because we want to be whole people.
WITHWARD, because we were made to live in community.
OUTWARD, because Jesus calls us to serve the world.
UPWARD, celebrating God's redemption of all things.