For at least a generation some Catholic communities have adopted the Jewish custom of the Seder supper.  The Seder or Paschal (also, Passover) supper is a thanksgiving meal celebrating God’s liberation of the Hebrew people from slavery in Egypt.  Jesus celebrated this ritualistic feast with his disciples the night before he died.  At that meal Jesus identified the bread and wine being offered to God with his own body and blood, which were to be broken and shed the following day.  The Eucharist thus finds its origins in the Jewish Passover supper.   

What happened to Jesus on Good Friday changed forever the meaning of Passover, at least for Christians.  Instead of seeing God’s definitive act in history being the freeing the Hebrews, Christians understand it in the world’s being saved from sin through Jesus’ crucifixion and resurrection from the dead.  We now can live unencumbered by past sins and undaunted by death because Jesus has won for us the ultimate victory over these nemeses which overshadow even slavery as evil. 

Jesus’ Paschal event is called a mystery because it is a sign of God’s unfathomable forgiveness and love for humanity.  The liturgy of the Church enables us to partake in Jesus’ Paschal mystery so that we may receive its salvific effects.  Especially the Eucharist gives us a share in the freedom that Jesus has won through his death and resurrection.  Liturgy also opens us to service.  For this reason, the Eucharist traditionally ends with the words, “Go, you are sent” (in Latin, “Ite, missa est”) meaning that Christ sends us into the world to bring his peace to others.