The passover meal celebrated the Jews' deliverance from slavery in Egypt (Exodus 13:3-10). It also had a much deeper spiritual application that would be fulfilled through His death. The Jewish nation had missed any future prophetic meaning of the passover.
On the night of the original passover, the Lord passed through the land of Egypt and judged the land by slaying all the firstborn men and beasts. The Jews had to slay a spotless lamb, take its blood and apply it to the door posts of their homes. They were commanded to remain indoors, under the covering of this blood until morning. When the Lord passed through the land at midnight to execute His judgment, He passed over the homes that had the lamb's blood on their doors and no one inside was hurt. This is a picture of the redemption that Jesus provides for us.
Everyone deserves judgment because of their sins. But, Jesus provided Himself as a spotless, sacrificial lamb for us, so that if we apply His blood to our lives by confessing Him as Lord, God will pass over us on judgment day.
Jesus was sacrificed on the 14th day of the first month of the Jewish year - the exact day and time that the passover lambs were being slain.
"Christ our passover is sacrificed for us" (1 Corinthians 5:7).