That night, God swept throughout the land of Egypt, killing all firstborn males left unprotected by that blood. Only those families who obeyed Moses' instructions were spared. Today, the lamb bone reminds us of the deliverance of the Jewish people by the shed blood of the lamb. If a lamb cannot be offered properly at the Temple, then the sages say, it should not be eaten at all. The bare bone which is raised at Passover reminds the Jewish people that their redemption as Jews remains incomplete until the Temple and its sacrifices are restored.
Full redemption awaits a future day.
The Jewish people have no altar, no holy place for blood sacrifice. All that remains is the bone. This is a mystery to most Jewish people. Most secular Jews, who find the very idea of sacrifice to be reprehensible and archaic, still observe the ritual. Orthodox Jews know what is missing.