Did Jesus or the Old Testament teach about the body of Christ?
No. The body of Christ is not mentioned in the Old Testament, nor is it even alluded to in Christ's earthly ministry. It is strictly a Pauline revelation, given through the apostle Paul, who presents it as part of the mystery.
The transcript explains that the body of Christ began to be called out when Paul, the apostle of the Gentiles, preached the gospel of the grace of God. It stresses that being a member of the body of Christ is what matters, not merely belonging to a congregation, because without that membership one is eternally lost. Once a person enters God's salvation, the Holy Spirit places them into the body of Christ, bringing eternal life, eternal salvation, and the hope of glory. The concept is described as a revelation only of the apostle Paul, never mentioned in the Old Testament and never alluded to in Christ's earthly ministry; it is strictly a Pauline revelation wrapped up in the predominantly Pauline word 'mystery.'