What IS the Church?

Jesus said, "I will build My church..." God sent Jesus into the world to re-connect created beings with the Creator. Jesus announced that, "even as the Father has sent me into the world...so I send you." So... is there an inter-connectedness between the incarnation and the mission of God that somehow converges in the church? How are we being "sent" by Jesus into the world? What is God's mission for us? Can the church primarily exist to care for its own members and in so doing, be what God intended it to be? Is this all some theological discussion, or is it relevant to why we exist as a church? What do you think?