Faith and Reason: When Freedom speaks with a Hebrew accent: Rabbi David J. Goldberg, Senior Rabbi at the Liberal Jewish Synagogue, London, considers the historic message of the feast of Passover, which is celebrated tonight.

THIS EVENING, Jews throughout the world will welcome in Passover the oldest, and the most symbolically potent, of all the Jewish festivals. At the Passover meal - the Seder - we will recount from an ancient liturgical text known as the Haggadah the story of the Exodus from Egypt more than 3,000 years ago. Led by Moses, the children of Israel made their escape from slavery to freedom. In every generation, the Haggadah enjoins us, it is our duty to instruct our children in the details of the Exodus story as if we personally had been redeemed from Egyptian slavery.

Because of its theme and associations, Passover is every Jew's favourite festival. In the words of the great German-Jewish poet Heinrich Heine, 'Since the Exodus, Freedom has always spoken with a Hebrew accent.' The unhappily assimilated product of two cultures, he also wrote, in one of his short stories, 'Jews who long have drifted from the faith of their fathers . . . are stirred in their inmost parts when the old, familiar Passover sounds chance to fall upon their ears.'

In ancient times, the Passover meal consisted of the paschal lamb, eaten together with unleavened bread - matzah - and bitter herbs - maror - in family groups, as a commemoration of the original exodus, which occurred in the springtime. The Hebrew word for Passover - Pesach - comes from a verb meaning 'to limp' or 'to skip', and was probably used to describe the first unsteady steps of a new-born lamb.

According to the Biblical narrative, the Children of Israel offered up a sacrificial lamb, daubing its blood on the doorposts of their houses so that God would 'pass over' and spare them when bringing the Tenth Plague against the first-born of the Egyptians. The bitter herbs represented the bitterness of slavery, and the matzah recalled their hasty flight from Egypt, before their dough could leaven.

At times of oppression and curtailed liberty - as under Roman rule - the festival's message had particular resonance. Because it was the paradigm of God's redemptive intervention in the history of Israel, the celebration of Passover aroused fervent longing among Jews for a second deliverance from bondage, led by a new Moses - the Messiah, whose coming would be presaged by his harbinger, Elijah the prophet.

The origins of the Messianic doctrine in Judaism are complex and occasionally contradictory, but primarily the Messiah was understood to be a political-military ruler, a descendant of the House of David, who would expel the foreign invader and restore the Jewish state. Grafted on to this concept of a divinely chosen leader was the description in the Book of Isaiah of an idealised future king who would promote justice, fidelity to the Law's commandments, and peace.

Clearly, Jesus of Nazareth did not conform to this Messianic pattern. He did not advocate a military uprising against Rome, or preach a political programme. His was a spiritual message, of repentance and rebirth. The archetypal predecessor whom he most closely resembled was Isaiah's Suffering Servant, a 'man of sorrows' who would be 'wounded for our iniquities, bruised for our transgressions', destined to be 'brought as a lamb to the slaughter' and buried with the wicked. This Messiah was no guerrilla leader or future earthly king. He was, rather, a sacrificial victim, a teacher by his word and example, and by his life and death.

According to the Synoptic Gospels, it was the seder meal that Jesus shared with his disciples before his arrest and trial. The Gospels describe how he broke the unleavened bread with them, blessed the wine, and sang the traditional hymn of deliverance, the Hallel, which is recited on the first night of Passover.

But Mark, Matthew and Luke make no mention that Jesus ate the paschal lamb. The reason was because they believed that Jesus himself was the paschal lamb, to be sacrificed in order to redeem mankind. A few years later, Justin Martyr made the theology explicit in his Dialogue With Trypho: 'The blood of the pascha, sprinkled on each man's doorposts and lintel, delivered those who were saved in Egypt, when the first-born of the Egyptians were destroyed. For the pascha was Christ, who was afterwards sacrificed . . . And as the blood of the Passover saved us who were in Egypt, so also the blood of Christ will deliver from death those have believed.'

For the followers of Jesus, the unleavened bread and wine of the Passover were transformed into the Blood and Body of Christ, sanctified in the sacrament of the Eucharist. It is one of history's little ironies that the pagans would accuse early Christians of devouring the flesh of infants and using their blood in the Eucharist - the Blood Libel charge later levelled by credulous Christians against the Passover meal, with dire results for Jewish communities in Europe throughout the Middle Ages and beyond.

Early Christianity celebrated the resurrection of Jesus at the same time that the Jews observed Passover, according to the lunar computation of the Jewish calendar. Hostility was inevitable, given that Jews rejected Jesus as the Messiah, and at the Council of Nicea in AD325, presided over by the emperor Constantine, Christians were prohibited from celebrating Pascha (Easter) at the same time as Passover, to 'have nothing in common with the detestable Jewish crowd'. However, since the date of Easter depends on the vernal equinox, it usually falls in close proximity to Passover.

The common origins and interwoven themes of Passover and Easter serve as an apt metaphor for the shared yet divergent paths taken by Judaism and Christianity. For Jews, the Messiah is yet to come. Christians await his Second Coming. Both religions are poignantly aware that humanity is still unredeemed, that physical freedom is denied to many people in many lands, and that spiritual liberty is enslaved in the prison of our material appetites.

For both Jews and Christians, therefore, the Passover promise has still to be fulfilled. We and previous generations have not proved worthy to witness the time of redemption. That awareness adds a sober tinge to our festive celebrations. If it leads us to explore the path of reconciliation in a spirit of humility, mutual respect and frank acknowledgement of our human fallibility and failings, then we might help to bring a little nearer that Messianic age so devoutly prayed for at Passover and Easter.