The tenth plague, the death of the firstborn, introduces Passover. God certainly knew which homes belonged to Egyptians and which were Israelites. Why didn't he simply skip the Israelite homes? Why did God require blood on the doorframe of a house to protect it from death?
Let's go back to the beginning. When Adam and Eve chose their own desires rather than God's, they chose death. Judgment was immediate. They were instantly severed from God. That is dead because God is life, and this has been passed on to each and every one of us. We are all dead, separated from God because of sin. But Grace began immediately, as well. God allowed Adam and Eve, though dead, to keep breathing, and he launched his plan of salvation.
Fast forward to Exodus 12. The judgment that would be passing through the land was just. Every family deserving of death would be visited by the destroyer, and every family deserved death. Even the Israelites. That Passover night, the destroyer would be indiscriminate. Egyptian or Israelite, either would be visited, unless...
Blood on the doorframe was a sign that death had already been to that household. A substitute had been sacrificed, a lamb approved by God had paid the price. The death of the lamb covered the sins of the household.
Fast forward to A.D. 30.
The next day John the Baptist saw Jesus coming toward him, and said, "Behold, the Lamb of God, who takes away the sin of the world!" ~John 1:29
Almighty God, Your goodness runs deep, but I choose to wallow in the shallows of my desires. Still, despite my rebellion, Your grace seeks me through the loving sacrifice of Your Son. Your righteousness consumes my own passions, and my desires become Yours. In response to Your never-ceasing, never-ending love, I live thankfully and joyfully in a world made new again.
What a wonderful Savior. What amazing grace.