God's patience had run out, and His final judgment--death to the firstborn--was about to fall. Note that death was to come to all, unless they were protected by the blood of the lamb. From a human point of view, there was no difference between the firstborn of Egypt and the firstborn of Israel; the difference was in the application of the blood. All men are sinners; but those who have trusted Christ are "under the blood" and saved. This is the most important difference in the world.
The Passover is instituted in chapter 12. The birth of the nation of Israel, its deliverance from bondage, and a change in the calendar is announced.
The Jews have two calendars--a religious and a civil--and the Passover marks the beginning of their religious year. The Passover illustrates the Christian's salvation through the blood of the Lamb. Just as the Israelites were shielded from the death angel, so the believer today is shielded from the wrath of God through faith in the Lamb of God (1 Corinthians 5:7). The unleavened bread showed the clean-cut separation of the Israelites from Egypt.
The lamb had died for the firstborn; now the firstborn belonged to God. The Jews were a "purchased people," just as born-again believers are purchased people (1 Corinthians 6:18-20). The nation would forever honor the Lamb by giving their firstborn--their best--to the Lord.
God led His people, not necessarily the nearest way, but the way that was best for them, just as He does today. He always makes His will clear to those who are willing to follow. He saves us, feeds us, guides us, and protects us.
