In Matthew 20, the mother of the sons of Zebedee came to Jesus and asked if her two sons could sit on Christ’s right hand and left in the kingdom. He asked if they could participate in His baptism, and if they could drink the cup that He would drink. He replied that they would in fact do so, but that to apportion the places to His right and left was not His to give. When the other disciples heard this, they were indignant—and it was presumably not because they were filled with humility and were upset at the arrival of pride in the hearts of two of them.
Jesus takes the occasion to teach them that authority in the kingdom of God did not work the same way that striving for power works in the world’s way of doing things. Remember that He said that they would in fact share in His baptism, and they would in fact drink from His cup. But they clearly had not done so yet. That is because His baptism is His death, and when we are baptized we share in His death. His cup is the cup of the new covenant, and it is a cup of death, a cup of blood. What does it mean for us to partake of Him? It means that we die. Among other things, this Supper means that we die to all angling, striving, grasping, and positioning. We die to it, which is not the same thing as taking that self-aggrandizement and trying to slow it down a little bit. Death slows it down completely.
This means that we partake of His death. It means we are called to share in His sufferings. And it means that this observance of the sacrament is a deference of death, an observance of organized deference to one another—love.