Ok. Let’s take the one for Shabbat; it’s the one I’m most familiar with. It says: Blessed are You, Lord our God, King of the universe, who has brought forth bread from the earth. Blessed are You, Adonai our God, Sovereign of all, Creator of the fruit of the vine.
So, bread is a worldwide staple food that nourishes us. It is considered to be a gift from God that glorifies God and God’s gift of creation. Wine is also a worldwide staple that cheers us and makes us glad. It, also, is a gift from God that glorifies God and God’s gift of creation.
Jesus is considered (by Christian theology) to be the “staple” or fundamental of life. The texts identify him as “bread of life.” Jesus brings abundant life (and that cheers us). Being the firstborn of creation, Jesus “personifies” God and also embodies a humanity in perfection.
The Eucharist comes to us more or less from the tradition of the Roman symposium, or dinner party. In the typical symposium, bread was broken and wine was poured. There was always a libation or “toast” given over the wine. When Jesus broke the bread and said, “This is my body given for you,” it may well have been a theological teaching of Jesus-as-staple-nutrient — a nutrient for both body and soul. Wheat “gives its life” for the life of the world. Wine is poured out for our abundance. It brings a different ontology to bread and wine, recognizing the world as God’s body that is given for us and our life. So, no, we’re not eating flesh and blood. Rather, we’re sharing in the cycle of life by “taking into ourselves” the life God gives us. The earth feeds us. One day, we will feed the earth. To consume something is to make it part of oneself. In Eucharist, we’re making Jesus — the bread of life — part of ourselves.