The observance of the Passover meal began in Egypt when God liberated His people, Israel, from the bondage of slavery. Moses had warned Pharaoh that God would send a series of plagues upon Egypt unless the people were freed. Pharaoh refused repeatedly. The final warning was that death would come to every firstborn male in the land if Pharaoh did not release the Hebrew people. Again Pharaoh refused. God instructed His people to sacrifice a year old lamb, without blemish, and apply the blood of the lamb to the doorposts of their homes (Exodus 12). The Death Angel would thus "pass over" their homes and they would be protected. Any home that did not have the blood covering would lose their first born.
The Passover has been celebrated ever since that time as a remembrance of God's deliverance of His people from bondage. The Passover Lamb, however, was revealed and fulfilled when Yeshua (Jesus) laid down His life as a sinless, spotless sacrifice for the sins of all mankind. This is the means by which all can receive eternal life.
Yeshua (Jesus) was crucified on a cross as foretold in scripture (Psalm 22). He suffered the shame and the cruelty of this death as the ultimate sacrifice for our sins. He rose from the grave victorious on the third day and took His place at the right hand of The Father as our High Priest, where He continuously intercedes for us.
When we die, we will meet Yeshua (Jesus) face to face and give an account of our lives. If we have not acknowledged Him as our Lord, His blood will not cover our sin, and we will be cast into the lake of fire. If we have confessed that He is Messiah, and have given our lives to Him, we will remain with Him for eternity. Yeshua (Jesus) is our Passover Lamb.
John 1:29 Behold the Lamb of God, which taketh away the sin of the world.