First, read the whole passage in context.
Quote:
29 For no one ever hates his own body, but he nourishes and tenderly cares for it, just as Christ does for the church, 30 because we are members of his body. 31 "For this reason a man will leave his father and mother and be joined to his wife, and the two will become one flesh." 32 This is a great mystery, and I am applying it to Christ and the church.
This is the NRSV translation, which doesn't include the flesh and bones part. Nevertheless, your question still applies.

Note what Paul says about his statement being a great mystery. Are you literally one flesh with your spouses? Literally? Of course not. But you are, in the Christian mystery sense. So are Christ and His Church, in the same mysterious sense.

We are literally the body of Christ because we do (hopefully) what Christ would do if He were still on earth in His pre-resurrection human form. More accurately, it's what we're called to do, and what we've promised to do. Being human and not divine, we of course fail repeatedly. But we still do try, and occasionally succeed. When Christ told us to feed the hungry, give drink to the thirsty, etc., and to love God and love our neighbor, He was in essence telling us to be Him after He had ascended.

The body of Christ that we receive in Communion is the body of Christ in the meaning Jesus had when He said, "This is my body." That's a whole new mystery. We don't understand it and we don't claim to. We just believe it because He said it and the Apostles taught it.

Questions about whether we're eating ourselves are ridiculous. Funny, but ridiculous. And that's because, you just don't get it.

Radar