The Body of Christ
The apostle Paul instructs us, "Ye are the body of Christ, and members in particular" (1 Corinthians 12:27). Then he says more specifically, "As the body is one, and hath many members, and all the members...being many, are one body: so also is Christ" (12:12).
Paul is telling us, in essence, "Take a look at your own body. You have hands, feet, eyes, ears. You're not just an isolated brain, unattached to the other members. Well, it's the same way with Christ. He's not just a head. He has a body, and we comprise its members."