Paul had to be confused; a heavenly voice was accusing him of persecution. "Who are you, Lord?" And the voice answered, "I am Jesus, whom you are persecuting." During His earthly ministry Jesus had told the Apostles, "as you did it to one of the least of these my brethren, you did it to Me" "(Mt 25:40); and He manifested that truth to Paul in the first moment of his conversion, "Why do you persecute Me?" It was a truth that cut Paul to the heart and shaped his whole theology - the Church is the Body of Christ, a mystical extension of His very Person!
Look at what Paul wrote later in life:
“Just as a body, though one, has many parts, but all its many parts form one body, so it is with Christ. For we were all baptized by one Spirit so as to form one body—whether Jews or Gentiles, slave or free—and we were all given the one Spirit to drink. Even so the body is not made up of one part but of many … If one part suffers, every part suffers with it; if one part is honored, every part rejoices with it.” (1 Cor 12: -14,26).
"The gifts [Christ] gave were that some would be apostles, some prophets, some evangelists, some pastors and teachers, to equip the saints for the work of ministry, for building up the body of Christ, until all of us come to the unity of the faith and of the knowledge of the Son of God, to maturity, to the measure of the full stature of Christ.
... speaking the truth in love, we must grow up in every way into him who is the head, into Christ, from whom the whole body, joined and knit together by every ligament with which it is equipped, as each part is working properly, promotes the body’s growth in building itself up in love." (Eph 4:11-16)That first truth that Jesus impressed upon Paul moved him to write things that, were it anyone but the great Apostle Paul saying them, many a Christian would say bordered on the heretical!
“[God] has put all things under Christ’s feet and has made him, thus exalted, head of the church, which is his body: the fullness of him who fills the universe in all its parts” (Eph 1:22)
"If we are unfaithful, [Christ] will still remain faithful, for he cannot deny himself" (2 Tim 2:13)That is how incredible the union is between Jesus and His Church - you cannot have One without the other! Mind. Blown.
Hey, so long as I'm at it, I'll throw out one more (one I did a whole post on last week): Paul even identified the Church as "the pillar and foundation of truth" (1 Tim 3:15)! That's a mighty big claim ... but if she is the very Body of Christ, the One Who is "the truth" (Jn 14:6), then it makes perfect sense.