Christ our Passover lamb was sacrificed for us, Paul says in 1 Cor 5. We no longer choose Passover lambs and sacrifice them and keep that feast. Jesus instituted a new festival for us, on the same night He was betrayed, on the night of Passover. When we eat this bread, it reminds us of the broken body of Jesus on the cross. Torn skin, bloody and scourged. And at the same time, much worse, torn apart fellowship from His Father, for the first time in forever. When we hold and drink the wine in this cup, we participate in the new redemption, the new exodus. Israel came out of Egypt, and Moses sprinkled them with blood and called it the blood of the covenant. Jesus delivers us from the bondage of sin guilt, and gave us this cup, calling it the new covenant. The blood of the lamb kept the angel of death at bay for Israel. The blood of Jesus covers us from God's understandable wrath against our sin.