Which book of the New Testament contains Paul's description of the church as a body of many parts?

The correct choice is the book of 1 Corinthians, where Paul uses the metaphor of the church as a body to illustrate the diversity and interdependence of its members. In 1 Corinthians 12, Paul explains that just as a body is made up of various parts, each with its unique function, so too is the church comprised of different individuals with distinct roles and gifts. This analogy emphasizes the importance of unity among believers, regardless of their differences, and highlights that every member plays a crucial role in contributing to the overall health and mission of the church.

The other books mentioned, while they may discuss aspects of the body of Christ or the church, do not focus on this metaphor to the same extent or with the same detailed elaboration as found in 1 Corinthians 12.