All the firstborn in the land of Egypt were smitten that night--all died--but those under the blood were passed over because they died in a lamb. Christ the Lamb of God died in place of multitude no man can number that the plague should not be on his children to destroy us. Those who are brought by God to believe on Christ, live and go out free (Romans 8: 1; Ephesians 1: 6-9.) Believers continue to keep the feast until this day through faith "with the unleavened bread of sincerity and truth."
God shall pass through once more at the great day of judgment. Only those under the blood of Christ will be saved. If you have not believed on Christ flee to the Lamb, today!