When the Angel of the Lord saw the blood on the houses of God’s people, he “passed over” those houses and all inside the home were allowed to live. The Feast of Unleavened Bread was to serve as a yearly reminder of God’s passing over his people. The blood of the lamb also served as a yearly reminder that the death of an innocent lamb was necessary to preserve the lives of all inside of a household. When Adam and Eve sinned in the garden and discovered their nakedness, God in his grace sacrificed an animal to make clothes for them to cover their sin. From that time on, death was necessary to atone for (cover) sin. In the case of the Passover, the death of a lamb was even necessary to protect Israel from sins committed against them.
The book of the Leviticus is the third book of five in the Bible written by Moses along with Genesis, Exodus, Numbers, and Deuteronomy. Leviticus serves to help a redeemed people understand how to live as the holy people of God through obedience and sacrifice. As much as anything, Leviticus shows the people of God that holiness is not an attainable goal outside of God’s willingness to forgive through sacrifices and offerings.
Leviticus outlines a system of festivals, sabbaths, and sacrifices the Israelites are expected to cling to as God’s people. The sacrificial system of Israel was instituted by God to remind the people of the great cost of their sin and to create a system of atonement whereby the people of Israel might maintain their holiness. The sabbaths and festivals served as times of solemn rest during which work should not be done, but God should be worshiped and remembered.
Perhaps no festival or feast in ancient Israel was more important than the Passover (also called the Feast of Unleavened Bread). The Feast of Unleavened Bread was a time to remember and reflect upon God’s deliverance of Israel from Egypt’s bondage. After a period of time and plagues when Pharaoh refused God’s command to let his people go, God acted to force Pharaoh’s hand. The tenth plague enacted on the people of Egypt was the plague of the death of the first born.
Because Pharaoh refused to honor God, God warned that he would kill the first born from every household in Egypt. But, God promised to spare the children of Israel. After Pharaoh’s final refusal, Moses led Israel to honor God’s command.