In the New Testament Paul sometimes refers to the Church as “the body of Christ.” But using “body” as a metaphor for an entity composed of constituents who are considered parts or members of a body didn’t originate with Paul.
In the culture of Paul’s day, the comparison of the state to a body and the citizens to it’s components, was well-known. Seneca, for example, referred to the Roman empire as a body and the people as its limbs.
As the early Christians so often did, Paul coopted this Roman political concept. Christians were not to consider themselves the component parts of the body of state. Rather, they were the body of Christ.
If we are the hands and feet of a body, which body is it? The state? Or Christ?