The following is a summation of Exodus 12:1-11:
  Before the ten plagues in Egypt, Moses and Aaron were instructed to institute a solemn feast.  They were to do this one specific night and then to commemorate that night by observing it every year.  The Israelites were slaves in Egypt…that night they would leave, quickly. 

  They were to take a lamb on the 10th of that month and keep it until the 14th of that month.  It was to be an unblemished one year old male.  At twilight on the 14th they were to kill the lamb and take some of its blood and put it on the doorposts and the top of the doors of the homes in which they would eat that lamb.  They were to eat it roasted (with bitter herbs and unleavened bread) and be dressed ready to leave Egypt.  Their staffs were to be in their hand…ready to move out.  “…This is the LORD’S Passover.” 
(Exodus 12:11) 

  Why? 
(NASB) Exodus 12:12 “For I (LORD God) will go through the land of Egypt on that night, and will strike down all the firstborn in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgments – I am the LORD.” 

  Did you notice?  The 10 plagues were judgments against the gods that Egypt worshiped.
  The Lord God executed judgments against the gods of Egypt – in whom do you believe if not the living God of the Bible? 

  Think with me about the blood of the Passover Lamb that was applied to the doorposts and top of the doors of the homes.  All who were inside those homes with the lamb’s blood were saved from death.  Jesus Christ is the Passover Lamb whose blood saves all who turn to Him by faith in Him. 

(NASB) Exodus 12:13 “The blood shall be a sign for you on the houses where you live; and when I see the blood I will pass over you, and no plague will befall you to destroy you when I strike the land of Egypt.” 

  That is exactly what God does for all followers of Christ.  Jesus (Messiah) died at twilight on Passover.  He was (and is) the Passover Lamb. 

  God’s love provided the Passover Lamb so God’s judgment would Passover any and all who turn to Jesus as their Savior, their Redeemer.  Do you know God’s love in this way for yourself? 
  For whom are you to pray to be protected by faith in the blood of Jesus? 

“Behold, the Lamb of God who takes away the sin of the world.”

John 1:29 NASB