‘The Last Supper’ by Bartolome Carducho. PHOTO: BRIDGEMAN IMAGES

Easter stalks Passover. They arrive together every spring, like the daffodils and magnolia blossoms. This year, Easter Sunday falls as the eight-day Jewish festival nears its end. Over the years, I have come to see that Christianity’s most important day recapitulates Passover. Both holidays face head-on the daunting power of death—and both announce God’s greater power of life.

In March, my wife, who is Jewish, was on the phone, herding her parents, uncles, brothers and cousins. “No, it’s not Tuesday. The first night of Passover is on Monday this year.” She made arrangements for the Seder, the festive meal with a traditional liturgy that retells the familiar story of the Exodus. Emails and texts were exchanged to sort out who would bring what, and this past Monday night we sang and recited the age-old prayers and set out a cup for Elijah, the harbinger of the messianic era. We ended, as always, with the declaration: “Next year in Jerusalem!”

Now, just a few days later, the holiest days of the year for Christians are under way. As the solitary Catholic in my Jewish household, I’m planning to head to church on Saturday night for the Easter Vigil—where I’ll be celebrating Passover once again.

In Romance languages, the connection between the Jewish and Christian holidays is explicit. The Hebrew word for Passover is Pesach. In French, Easter is Paques. In Italian it’s Pasqua. In many other languages, the word for Easter is simply a transliteration of the Greek word for Easter, Pascha. English is among the exceptions. Our word, Easter, is German in origin, coming from the archaic word for new life, which is to say, resurrection.

In the New Testament, Passover and Easter are tied together. Jesus enters Jerusalem and gathers his disciples to celebrate the Passover meal, memorialized by Christians as the Last Supper. Soon, he is arrested, tried and executed on the cross, dying just before the beginning of the Jewish Sabbath. Then, on Sunday morning, his followers are astounded to find their teacher appearing to them as one alive, not dead.

Some early Christians repeated the sequence exactly, marking Easter on the same day as Passover, regardless of the day of the week. Others adopted a different kind of rigor, insisting that Easter dawn on a Sunday, as it had for Jesus’ disciples. They celebrated Easter on the first Sunday after Passover, as we do as well (with rare exceptions). The difference ignited fierce debates in the early centuries of the Church. But all agreed on the central point: The lunar cycle that sets the date for Passover also determines Easter.

The relation between Passover and Easter runs deeper still. Because I’m married to a Jewish woman who decided that having a Christian husband was a reason to become more Jewish, not less, I’ve been repeating the biblical pattern for more than 30 years. This has led me to see that Easter doesn’t just share the same week with Passover. They are about the same thing: In both, the dead rise to new life.

This profound connection is not evident to most Christians. Our understanding of Passover emphasizes the blood of the Passover lamb, which Moses commands the Israelites to put on their door frames so that the Angel of Death, sent to kill the firstborn of Egypt, will “pass over” them. This image—the lamb whose blood saves—is taken up in the New Testament, especially in the Gospel of John and the Book of Revelation.

The north apse of the Basilica of the National Shrine of the Immaculate Conception in Washington, D.C. PHOTO: JOHN GREIM/LIGHTROCKET/GETTY IMAGES

As a consequence, the religious imagination of most Christians connects Passover to Good Friday, the day on which we remember the crucifixion and death of Jesus. The theological meaning is plain: Jesus himself is the Passover lamb, offered as a sacrifice for the whole world.

Origen, a profoundly influential early Christian thinker, reinforced this interpretation. He thought that the Greek word for Passover, pascha, stemmed from the word for suffering, paschein, which the New Testament uses to describe Jesus’ agonizing death. In medieval paintings, John the Baptist is often portrayed pointing up to Jesus on the cross with the words of John 1:29 emblazoned: “Behold, the Lamb of God, who takes away the sins of the world.”

It took me many years to realize that my Christian assumptions were almost entirely wrong. Blood and sacrifice are integral to the meaning of Jesus’ death, to be sure. But that turns out to have very little to do with the way in which Jews actually celebrate Passover.

The reason has to do with history. During the time of Christ, Jews came from the surrounding provinces to bring lambs to the Temple in Jerusalem for the Passover sacrifice. It was at this time that Jesus shared a sacrificial meal with his disciples. Not long after the time of Jesus, however, a Jewish political uprising prompted the Romans to take the drastic measure of destroying the Temple in Jerusalem and consecrating the city to their own gods.

This forced a revision of Passover. With no Temple, sacrificing lambs was not possible. The Jewish authorities in ancient times refocused the Passover celebration on the shared meal. The result is the Seder, the set order of prayer and scripted retelling of the Exodus story that Jews now use.

The blood of the lamb is mentioned in the Passover Seder, but only in passing. What comes to the fore instead is the obligation to recall what God has done for his people: “We were slaves to Pharaoh in Egypt, and the Lord, our God, took us out from there with a strong hand and an outstretched arm.”

Put in Christian terms: The Passover Seder recalls and celebrates the resurrection of the people of Israel.

Today we tend to think of slavery strictly as an injustice, which of course it is, and some modern Seders treat the Passover as the triumph of justice over oppression. But this is not the traditional view. In the ancient world, slavery was not just a hardship for individuals but a kind of communal death. An enslaved nation can survive for a time, perhaps, but they have no future. A people in bondage is slowly crushed and extinguished.

At Passover Seders, Jews eat unleavened matzah and spill out drops of wine in symbolic memory of the biblical 10 plagues. PHOTO: DPA/ASSOCIATED PRESS

The notion of slavery as a form of death is accentuated in the story told in the Passover Seder. The small clan descended from Abraham settles in Egypt. They are fruitful and multiply, becoming numerous and mighty. The glow of life in the people of Israel arouses Egyptian resentment. Set upon and subjugated, they are ground down by hard labor and harsh oppression. But the descendants of Abraham call out to God—and he raises them up out of slavery, parts the Red Sea, and delivers them from Pharaoh’s murderous anger.

Judaism is realistic. Passover does not promote a dreamy optimism or cheery confidence that God will keep everything neat and nice. Even the chosen people are vulnerable to oppression and murderous hatred. There’s room in Passover for Auschwitz.

The New Testament makes a bold promise. Whoever believes in Jesus shall not perish but will have eternal life. But Christianity also takes an honest approach, which makes believers take a long, hard look at death. The central symbol of Christianity, the cross, evokes a brutal execution. For Catholics, the Saturday between Good Friday and Easter is the only day of the year on which the Eucharist, the power of eternal life, is not provided. On that day we must endure death’s awful emptiness, in a spiritual way, just as, sooner or later, we must feel death’s terrible blows in brutal, literal ways.

It is a mistake to think that Christian faith somehow denies or evades the reality of death. In a church in Isenheim, Germany, there is an early 16th-century altarpiece by Matthias Grünewald. It depicts Jesus dead on the cross, his fingers gruesomely contorted in final agony. For Christians, the crucified Messiah is the dead soldier, half buried in mud, his face contorted and body torn. He is amid the bodies uncovered in mass graves.

The early Christians did not celebrate Easter with sunrise services. They gathered in the deepest darkness, long before dawn, for the Easter Vigil, which has been restored in many churches, including the Catholic Church. In the Vigil, Christians are like the Israelites fleeing with Pharaoh’s army. Easter begins in a night-darkened church. We are in the valley of the shadow of death.

In the story of Exodus, the Israelites make it through the split waters of the Red Sea to dry land. But they are not simply safe. God releases the waters, and Pharaoh’s army is destroyed.

So it is at the Easter Vigil. A chant known as the Exultet announces that the darkness shall not triumph. “Be glad, let earth be glad, as glory floods her.” With a haunting refrain, the ancient song links Passover to Easter: “This is the night,” we are told, “when once you led our forbearers, Israel’s children, from slavery in Egypt and made them pass dry-shod through the Red Sea.” And “this is the night when Christ broke the prison-bars of death and rose victorious from the underworld.”

Passover does not teach Jews that oppression is not real and suffering not bitter. The lesson is more powerful: God favors the people of Israel with his Torah, and its sweetness outweighs every setback, evil and disaster.

Nor, then, is Easter a simple springtime celebration of life. The resurrection of Jesus reveals something more urgent and shocking: God favors the sons of Adam with a triumphant love in the person of Jesus, the Christ. And that love does not fend off or parry death, but destroys it, just as light overcomes darkness.

We live within a mortal frame, which means that Jews and Christians do not experience God’s triumph over suffering and death, at least not directly. Instead, we perform it, entering into its reality in a partial but authentic way.

For Jews, there is a prayer said for the dead, the Mourner’s Kaddish. It’s an astounding statement, for it does not mention death. It’s an arrogant refusal to acknowledge death’s claim upon our anguished souls, extolling instead the power and goodness of God. At the grave of someone he loves, a Jew’s head may be bowed with grief, but as he recites the Mourner’s Kaddish, his prayer looks joyfully upward. He does not deny psychological realities. Death brings terrible suffering. It oppresses us. But his prayer denies those realities a final say: God has raised up Israel.

A Catholic funeral enacts the same pattern with equal intensity. Most religions regard death as profane and keep it far from their sacred sanctuaries. Christians, by contrast, allow death to come into their churches.

At a Catholic funeral, the casket sits in the middle of the church. The priest undertakes the prayers and rites that make Christ present, and the mourners come forward to receive the Eucharist, the body of Christ and bread of life. It’s a bold defiance. To receive the Eucharist only a few feet from a dead body puts a stick in death’s eye. This does not mean ignoring the tears and anguish that death brings, but it denies them the final say: Christ has been raised from the dead.

There is an ancient sermon about Easter by an unknown preacher. It recounts the traditional image of the crucified Jesus descending to Hell to break the chains that hold the dead in bondage. He seeks Adam and Eve, the original man and woman. Finding them in the deepest tomb, he smashes down the prison door. He shakes them awake with these words: “You were not made for death!”

We were not made for death. The Almighty delivers his people. He unlocks the prison of darkness and shatters the power of death. This is the meaning of Easter, the Christian Passover.

Mr. Reno is the editor of the religious journal First Things. He was formerly a professor of theology and ethics at Creighton University.