I'm sure that there are lots of intricate discussions about scripture mentioning the ritual of the bread and wine.
Simplicity, my friend.
What you eat and drink physically becomes part of your body. What you eat and drink spiritually becomes part of you. That's all there is to it, beyond just doing the ritual as a symbol for spiritual commitment.
John 6, somewhere around 40.
Jesus spoke in parables, even to His disciples.
Sorry Brother, its much deeper than that. ALL(NOT EVEN ONE EXCEPTION) the Early Christians knew the Eucharist is truly the Body and Blood of our Lord. Look.... http://www.therealpresence.org/eucharst/father/a5.html