How does Paul use the human body and its central nervous system to explain the Body of Christ?
Paul uses the human body as an analogy: the head and mind are the headquarters, and the central nervous system causes the nerve endings and whole body to function as one. Similarly, the Body of Christ has many members—believers worldwide—yet remains one body, all part of Him.
Les explains that in 1 Corinthians 12:12 Paul is simply using the human body as an illustration. The central nervous system and the mind are the very core of our being; everything we say, think, or do originates in the head, in the mind. Then the nerve endings respond, and the whole body functions, but it all has its headquarters up there. Paul uses that as an illustration of the Body of Christ, a new term not found in the Gospels; it is a Pauline revelation. The body has many members—fingers, toes, eyes, ears, arms, legs—but not twenty bodies. It is one, and all are part and parcel of Him. Verse 13 sets the Body of Christ as every believer around the world, regardless of color or denominational handle, if they are a believer.
For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ.