"In each and every generation we are obligated to see ourselves as if we personally left Egypt." This statement, from the haggadah, the book used to tell the story of Passover, sums up the importance of the seder, the ritual meal held in the home (and/or the synagogue) on the first two evenings of Passover.
For Jews, this holiday celebrates the journey of the ancient Hebrews from the slavery of Egypt to the freedom of the Promised Land-Israel, as told in the book of Exodus. For Christians, who may be celebrating Passover with Jewish relatives or friends, Passover offers an opportunity to enrich their understanding of the roots of Christian traditions and join in affirming the shared values of freedom, family, and faith.
The greatest challenge for a Christian participating in a Passover seder is to see the rituals and symbols through Jewish eyes. Many Christians are familiar with Passover only as it is sometimes observed in the Christian tradition. Some churches even have a "Passover" meal on Maundy Thursday or Holy Thursday, the Thursday evening before Easter. This meal recalls Jesus' Last Supper, which according to the synoptic gospels (Matthew, Mark, and Luke) was a Passover seder.
However, the description of the Last Supper in the New Testament does not offer enough information to conclude definitively that it was a Passover meal. Beginning a meal with drinking wine and breaking bread could have been part of a Sabbath evening meal or even a weekday meal. Indeed, according to the Gospel of John, the Last Supper took place the evening before Passover and Jesus was crucified on the eve of Passover at the time of the Passover offering (for, according to John, Jesus is the Passover offering).
Regardless of whether or not the Last Supper was a Passover seder, Passover plays a crucial role in understanding Easter in particular and Christianity in general. Just as for Jews Passover represents the redemption from slavery and the deliverance to freedom, for Christians Easter represents the ultimate redemption of humankind through the life and death of Jesus.
But while Passover is crucial for understanding the story of Easter, Christians should not allow these theological points to obstruct their understanding and observance of the Passover seder. Rather, the seder rituals and foods should be understood in the context of Judaism.
The most important symbols of Passover are the matzah (unleavened bread), maror (bitter herbs), and lamb or shank bone. The Bible tells us that we are to eat the lamb with matzah and maror (Exodus 12:8), and later on the rabbis insisted that we had not properly observed Passover if we did not explain these three items.
The lamb bone (some Jews use bones from other animals) represents the Paschal lamb whose blood was used to mark the Jewish homes which God passed over during the tenth and final plague, the slaying of the firstborn of the Egyptians. The sacrifice and eating of the lamb was central to the Passover ritual until the destruction of the second Temple in the year 70 C.E. (Common Era). Since we no longer make the Passover offering, it is traditional not to eat lamb at the seder, but to represent the lamb with a bone.
Jews eat matzah at the Passover seder to recall the haste with which the Hebrews left Egypt, baking their dough before it had a chance to rise (Exodus 12:39). Matzah also represents the bread of affliction, a reminder of the harsh servitude our ancestors experienced in Egypt. (Prior to the holiday Jews remove all bread and other products containing certain grains, replacing them with matzah and products made with matzah).
The maror (bitter herbs), usually represented by horseradish or bitter lettuce, reminds us that the Egyptians embittered the lives of the Hebrews (Exodus 1:14).
The other major symbol of the Passover seder is wine. Wine is a symbol of joy used to sanctify the Sabbath and Jewish holidays. On Passover, Jews drink four cups of wine, each representing one of the promises God made to the Jewish people: "I will free you from the labors of the Egyptians  and deliver you from their bondage . I will redeem you with an outstretched arm and through extraordinary chastisements . And I will take you to be My people, and I will be your God ." (Exodus 6:6-7)
An additional cup of wine is placed on the Passover table, the cup of Elijah. Toward the end of the meal, we open the door, anticipating the arrival of the prophet Elijah, who according to Jewish tradition, will usher in the age of the Messiah (Christians may recall that some people thought John the Baptist was Elijah).
Understanding these important symbols in their context will enhance one's appreciation for the seder meal and allow Jews and Christians to share a religious ritual meaningfully.