Speak to all the congregation of Israel, saying, “On the tenth of this month they are each one to take a lamb for themselves, according to their fathers’ households, a lamb for each household.” (Exodus 12:3)
The instructions were simple and straightforward. On the tenth day of the month, every family was to select an unblemished lamb or goat. On the fourteenth day of the month, they were to slaughter it and smear its blood on the doorposts of their houses. The blood would be a sign. God promised to pass over the houses marked with blood. The Hebrew word for "pass over" is pasach (פסח). We translate the word pesach into English as Passover.
The blood shall be a sign for you on the houses where you live; and when I see the blood I will pass over (pasach, פסח) you, and no plague will befall you to destroy you when I strike the land of Egypt. (Exodus 12:13)
The pesach lamb was a sacrifice, but it was not a sacrifice for sin. In discussing the Passover lamb, the Torah does not mention anything about sin, confession or atonement. Not every kind of animal sacrifice was meant for taking away sin. The blood of the Passover lamb was meant as a sign for God.
Did God really need a sign? Didn't He know which houses belonged to the Hebrews? Why did He need them to mark their houses with blood?
This can be compared to a father who told his son, "We are about to cross a busy street. Look both ways to see if any traffic is coming and tell me when it is safe to cross." Surely the father did not need his son to tell him when it was safe to cross. He could see for himself. Why didn't he simply tell his son when it was safe? He desired to teach his son the necessary precautions because he knew that one day it might save his life.
In a similar way, God wanted to familiarize His people with the concepts of sacrifice and blood atonement, because one day their lives would depend on it. If it was just a matter of making a mark on the house, it would not have been necessary to use an unblemished lamb (one that is fit for sacrifice) or even to use blood at all. The ritual of the lamb's blood at Passover provided Israel with a marvelous object lesson to prepare all of us for understanding the atoning work of Yeshua.
Every year, as we work through the stories of the slaying of the Passover Lamb, the exodus from Egypt, the crossing of the Red Sea and the rest of the narratives, we see the story of our salvation unfold in the language of Torah. The story of the Passover lamb is foundational for understanding the gospel. Just as the Passover lamb needed to be unblemished and flawless, we need a sinless substitute to take our place in judgment. Just as the blood markings protected everyone in the house, we need to take shelter under the spilled blood of Messiah. Just as the firstborn of those who did not prepare a Passover lamb were struck down, so too those outside of Messiah are without hope.
The Passover lamb was the avenue of escape that God provided for His people in Egypt from the devastating tenth plague. And it was not just for Hebrews. Had the Egyptians sacrificed a lamb according to the instructions and applied its blood to the doorposts of their houses, they too would have been spared. The sacrificial death of Yeshua is the avenue of escape that God has provided to spare us from condemnation and eternal death. One need not be Jewish to benefit; one only needs to be under the blood of Yeshua.