How does the human body operate as one even though it has many parts?
Paul illustrates that the human body is one unit though it has many members. Hands, feet, eyes, and ears all operate from a central nervous system and a central place of thinking, so the many parts function together as one body.
Paul uses the human body as an illustration in verse 12. He says the body is one but has many members, and all the members of that one body, being many, are one body. Hands, feet, eyes, and ears—everything that makes up our being—operate from a central nervous system and a central place of thinking, so they operate as one. He then says, “so also is Christ,” making the allusion to the body of Christ, where many different people from around the world, rich and poor, black and white, are one in Christ when saved by the same power and same gospel.