What does 1 Corinthians 12:14 mean?

Paul's illustration of the church—the collective name for all believers everywhere—is that of a human body. Like a body, the church is one organism. Like a body, the church has many, diverse members who serve a variety of functions. A body is not made up of identical copies of just one part; a healthy body requires a diversity of forms and functions.

Paul began this discussion with an explanation of the supernatural gifts God's Holy Spirit distributes to every believer as He sees fit. Soon, Paul will identify each believer's "part" in the body of Christ by the gifts we have been given to use to serve the rest of the church. Our gifts determine our function, and our function determines our part in the body of Christ. Every Christian has the Spirit. Every Christian has received a gift to use in service. Every Christian is a member of Christ's body.