The "cup" symbolizes the blood Jesus spilled in sacrificing His life. God is saying that through the blood of Christ, He is "sealing" His agreement of salvation with us. Though He had already promised it, Christ's blood certifies His agreement to justify us in preparation for salvation (Romans 5:9-10).

Such a monumental sacrifice must be fittingly remembered! If Passover becomes a mere ritual or pious habit, it loses its significance because Christ is not really being remembered with understanding and appreciation. In his letter to the Corinthians, Paul describes the brethren as rushing through the service, their minds so focused on their own bellies that they were treating each other with selfish disregard. Passover's purpose is not just to remember certain historical events, but to grasp the point of Christ's death. If we fail to comprehend its meaning, we are much more likely to treat His death unworthily.

Paul covers three major subjects in I Corinthians 11 and the chapters surrounding it: 1) our relationship with God, 2) our relationship with other members of the church and 3) spiritual liberty. Their common factor—the unique means by which all three are made possible—is the sacrifice of Jesus Christ.