“This cup that is poured out for you is the new covenant in my blood” (v20). The new covenant fulfilled and superseded the old one, which was the system of laws and sacrifices given to Israel. Jesus’ own blood, his sacrifice, provides forgiveness and cleansing for all who believe in him. The way of salvation is open – to Jews and Gentiles alike – through the cross. Israel had visible kings, armies, and a glorious temple, but Jesus’ glory was hidden by suffering (v44), weakness, and death.
The new covenant established by Jesus’ death appears to be weakness and foolishness, but to those who are being saved it is “the power of God” (I Cor 1:19).