And the most solemn week of the Christian year begins with Jesus arriving in Jerusalem to the hosannas of his followers who greeted him with palm branches as he entered the city to celebrate Passover. The gospel writers Matthew, Mark, and Luke tell us that what Christians now call the Last Supper, so often depicted in great works of art, was in fact a Seder. The Passover meal, argues the Encyclopedia of Catholicism, "celebrates God's liberation of the Jewish people and the continuing covenant with them. Such a celebration offers a model for understanding Christ's liberation of the world from sin through his death." It was at that meal, in his sanctification of bread and wine, that Jesus initiated the sacrament of Holy Eucharist. And some scholars believe that the wine for that first Eucharist came from the third cup of wine in the Seder, the cup of redemption, and the afikomen (about which more later) served as the bread. At the end of the meal, the gospels tell us, Jesus left to suffer his passion after "singing the Passover hymn." I like to think that particular Hallel, or song of praise, was the one I have insisted on—Psalm 136, that's the one where "his mercy endureth forever." Readers of the blessings in the Haggadah will hear very similar words to those in the blessings over the bread and wine in a Catholic Mass. A paper issued by the U.S. Catholic bishops reminds us that the Christian order of worship " takes its form and structure from the Jewish seder: the Liturgy of the Word, with its alternating biblical readings, doxologies, and blessings; and the liturgical form of the Eucharist, rooted in Jewish meal liturgy, with its blessings over bread and wine." The symbolism of the Easter season—the references to Jesus as the Paschal Lamb and to Christ as the Passover—those symbols make more sense once the Seder becomes familiar.