Another way to put this verse in an even broader context is to throw it against John 6, the “Bread of Life” discourse, in which Jesus keeps speaking of eating the bread that came down from heaven–which is his own body (and blood). Again, it’s a similar argument: if it is only a symbolic eating of the flesh/body of Christ, why doesn’t Jesus correct the misunderstanding of those who find this saying to hard to accept and leave? If the Catholic understanding is wrong, then this whole episode is absurd. Paul is here saying something that John clearly believes as well.