Remember the events in John 6 occured a year or so before Jesus' death and also that he is teaching one central thought at one setting..... That they to believe he is GOD in the flesh and they are to believe upon him for eternal life.
Notice the unique words spoken 3 times or more. "I give them eternal life and will raise them up at the last day" Now notice what he said with those words.
1) that everyone who sees the Son & believes in him. 2) whoever eats my flesh and drinks my blood 3) the one who comes to me.
Coming to Jesus, believing in Jesus & eating his flesh must all be refering to the same thing. In other words "eating his flesh" must be figurative language for "believing upon him". Likewise "coming to Jesus" must be the same as "believing upon him"