Nowhere and at no time is the Judeo-Christian heritage of Western civilization more prominent than at Passover season. Yet historically for the Jews in Christian Europe this time of year was the most perilous because of Passover’s connection to Easter.

Passover coincides for Christians with Christ’s Passion: the physical suffering after Jesus’ arrest in the Garden of Gethsemane just outside Jerusalem.

According to the Gospels, although the Romans arrested and crucified Jesus, various Jewish leaders, as well Judas, were involved in his prosecution. Many Jewish communities throughout the ages suffered and were attacked because of these “Christ-killer” narratives, especially during the early spring at Passover and Easter time.

Yet there is no denying the importance of Passover in Christian theology. Jesus is often called “the lamb of G-d.” Christian theologians speak of the pascal sacrifice of Christ. The Last Supper may have been a Passover feast.

The words or phrases used in French, Spanish, Portuguese and Italian for Easter are all derived from the Hebrew Pesach (Passover). In fact, the words for Passover in those languages are almost identical to those for Easter, indicating the close relationship between normative Jewish practices and the early Christians who considered themselves Jewish.

As for the English Easter, the etymology is unclear. Perhaps it has to do with traditions from the “East” and so derived from the old Anglo-Saxon term for Eastern. Perhaps it comes from an old Germanic term for “dawn,” evoking the rising sun as a metaphor for the risen Christ. Maybe the origin of Easter is found in an old Germanic goddess. Some scholars think Easter comes from the Latin for “white” or “dawn.”

Taken together, these theories convey the idea that Easter was an Eastern, ancient idea involving spiritual renewal, intimately connected with Passover as narrated in Exodus and the haggadah.

The paschal lamb was offered on the 14th day of the Hebrew month of Nisan. Jesus was crucified on Good Friday, the 14th or 15th of Nisan, according to most New Testament scholars.

Easter has two symbolic foods that parallel Passover: eggs and lamb. The eggs represent new life, renewal and the return of spring. For Jews, the Passover egg represents the koban hagigah, the special festival offering. The seder egg also symbolizes the promise of rebirth and spring.

The lamb for Christians is Jesus, who has saved the people of New Israel (the church) through the shedding of his blood. The shank bone on the seder plate reminds us of how our people were saved: The 10th plague, death to the firstborn, passed over the Israelite homes because of the lamb’s blood painted on the door posts and the cross beam connecting them.

Easter is closely connected to Pentecost, which traditionally marks the beginning of the church. Pentecost refers to the 50th day, as it occurs seven Sundays after Easter — the 50th day if you count Easter Sunday as Day 1.

Jews have a similar counting, sefirah. Beginning on the second day of Passover, 49 days (seven weeks) are recognized, the 50th day being Pentecost. Jewish Pentecost is the Festival of Weeks, Shavuot, when the Hebrew slaves became the Hebrew nation.

Jews call Shavuot the “time of the giving of the Torah.” It is the holy day of revelation.

Christian Pentecost commemorates the gift of the Holy Spirit enjoyed by the apostles on that day. The Jewish and Christian festivals both involve theophany, the appearance of the divine among the elected people.

The close connection between the Christian and Jewish holidays has a dark side for Jews beyond the calls for violence against the killers of Christ. Easter season also represents replacement theology.

Jesus takes the place of the Torah and his sacrifice becomes the means of salvation rather than mitzvot. This replacement theology was articulated by Paul, the apostle to the gentiles.

Many churches, Protestant and Catholic, have seders. I have led a few. Inviting a rabbi to lead a church seder is a friendly act. Given the violence of Easters past, it should be seen as a big step forward in Christian-Jewish relations. Because of replacement theology, however, it is also problematic.

The Easter-Passover closeness comes with challenges that can never be entirely overcome. If we are honest, it should be good enough that we now live together in peace.