This whole passage talks about how each part of the body has its own role, it's own job, each important to the functionning of the body. I can't help but wonder sometimes what my role is. As I was thinking of this, the following song came to mind, taken directly from Micah 6:8.
What is good and what the Lord requires of thee:
But to do justly
and to love mercy
and to walk humbly with thy God.