But since we learn in John 6 that "the flesh is of no avail" and using the principle that Scripture helps interpret Scripture, we deduce that this passage you quote is of little signifigance and is obviously a metaphor.
We can no more mean that we are "his body" than we could that a mere piece of bread is "his body."
SD
The flesh is of no avail for the spirit is what lasts and goes on. The body must die as it is designed to. Thus Jesus and the Apostles tell us to overcome the flesh (the carnal - the things we can touch and feel) and put your focus on the spiritual (the everlasting). The Body of Christ is spiritual. Scripture does help interpret scripture; but, one has to apply spiritual to spiritual, carnal to carnal, etc. Your contorted explanation sets the scriptures on their ear by applying the carnal to a spiritual issue. It's not amazing that you say it - it's amazing that you can't see it. This is why one needs the spirit of God. These things require him to understand. Carnal understanding cannot penetrate them. The small things confound the wise.