Is the term 'Body of Christ' used anywhere outside of Paul's writings?
No. The term 'Body of Christ' is a Pauline term used exclusively by Paul. Scripture never uses it anywhere else. It describes the spiritual organism of believers saved under the Gospel of Grace, contrasting with the Gospel of the Kingdom, which was Jewish and concerned with a different program.
Les explains that Paul never refers to the Gospel of the Kingdom because that was Jewish, but he is concerned with the Body of Christ, the Gospel of Grace, which goes to Gentiles. Les calls the Body of Christ a Pauline term exclusively, never used anywhere else in Scripture. He then shows that believers of the Gospel of Grace, being many, are one body in Christ, and every one members one of another. He illustrates with missionaries in Bolivia being in the same body as believers in Oklahoma and America, all members of that same spiritual organism regardless of station in life. This is crucial to understand.