Jesus wants his listeners to understand that the eating of his flesh would be done in a figurative way. So, to emphasize this, he says something still more objectionable if taken in a literal way.

“Unless you eat the flesh of the Son of man and drink his blood,” Jesus declares, “you have no life in yourselves. He that feeds on my flesh and drinks my blood has everlasting life, and I shall resurrect him at the last day;

True, Jesus’ teaching would sound most offensive if he were suggesting cannibalism. But, of course, Jesus is not advocating literally eating flesh or drinking blood. He is simply emphasizing that all who receive everlasting life must exercise faith in the sacrifice that he is to make when he offers up his perfect human body and pours out his lifeblood.