Summary: The cup and bread we bless signify our sharing in Christ's blood and body, uniting us as one body.
Brothers and sisters: The cup of blessing that we bless, is it not a participation in the blood of Christ?
The bread that we break, is it not a participation in the body of Christ?
Because the loaf of bread is one, we, though many, are one body, for we all partake of the one loaf.