What does 1 Corinthians 10:16 mean?
Paul is building to his final command about eating food that has been offered as a sacrifice to idols. His teaching will be clear and authoritative, but he also wants the Corinthians to understand it and to agree with him.He begins with the practice of Christian communion. In the following chapter, he will describe the purpose of receiving together both the cup as Jesus' blood and the bread as Jesus' body. He will quote Jesus' words: "Do this in remembrance of me" (1 Corinthians 11:24).
Here, though, Paul simply references the practice to make his point, describing it as the "cup of blessing that we bless" and the "bread we break." The reason the cup is a blessing is that it represents the blood Jesus shed to pay the price of our sin. As Hebrews 9:22 says, "Without the shedding of blood there is no forgiveness of sins." The bread is broken and distributed to each person to represent the breaking of Jesus' body.
Paul's point is that by consuming the bread and wine together, we all participate, symbolically, in the body and blood of Christ. They become part of who we are. He will go on to link this idea with the eating of food that has been offered to idols.