In Exodus 12 and 13 God brought his people out of Egypt, just as he had promised. While he was bringing them out, before they got to the Red Sea, he did what we would probably never expect: he had Moses preach to them and give them some rituals to observe as a nation! Why in the world would God do that? Is this really the time for sermons, rituals and laws? They are in the act of marching victoriously out of Egypt!
And God has already given a lot of these laws concerning Passover just days before. This must be very important to God! In fact, God (through Moses) related the ritual laws to Israel before the exodus event (Ex 12:1-28), during the event (12:29-13:16), and will repeat them again after the exodus (23:14-15). Israel will receive reminders of these laws AGAIN in Leviticus (23:4-8), Numbers (9:1-5; 28:16-25) and Deuteronomy (16:1-8). Why the importance?
God tells them:
“Remember this day in which you came out from Egypt, out of the house of slavery..” (Ex13:3, ESV).
The purpose of these rituals is to give Israel, a brand new, God-given, national IDENTITY. They've been slaves with no land, surrounded by a foregin culture, for over 400 years! They were just 70 people when they went to Egypt, but now they are a mighty nation (fulfilling God's promise to Abraham in Gen 18:18). God was establishing Israel’s identity as the chosen people of God that he redeemed by the blood of the lamb and brought out of Egypt with a mighty hand. Their identity is "a function of what God has done for them" (Peter Enns). These rituals would serve as “signs” and “memorials” (13:9) so they would ALWAYS REMEMBER what God had done for them. From now on, God would be known as the God who brought them out of Egypt (this phrase is seen throughout the rest of the Old Testament...in 18 books besides Exodus!).
God gives them the rituals of Passover, The Feast of Unleavened Bread, and God's Right of the Firstborn. These three ritual signs are to speak forever to Israel and their children of who they are, based on the exodus event. God's right of the firstborn (they must redeem, or buy back, their firstborn from God) will remind them of God's judgment of their enemies in the tenth plague, and that their own firstborn were spared because a substitute was killed in their place - the Passover Lamb. And Passover and the Feast will remind them of God's mercy on them as he rescued them through a substitutionary sacrifice; they come out by the blood of the lamb. This will shape their identity as a people - they must always remember God's salvation through the lamb!
God is also laying down the foundation in his people of great biblical themes that point to their Messiah, who will come. Themes of REDEMPTION, SUBSTITUTION, and SACRIFICE.
We can trace these rituals throughout the Old Testament. When Israel sins and drifts away from God, these rituals fall to the wayside. But in times of revival, when God brings their hearts close to him again, they express their love for God through obedience to these ritual laws he has given them. Read of King Josiah's celebration of Passover (2 Kings 23:21-23) when he sought to turn Israel's hearts back to the Lord. And later, after Israel's 70 years of exile in Babylon, when Nehemiah and Ezra led them back to their land, they celebrated these rituals with joyful hearts (Ezra 6:19-22).
Christians, this is fulfilled for us in Christ. Our identity is not in our job or our spouse, our income or the sin with which we struggle. Our identity is bound up in GOD, who chose us as his people and redeemed us with the blood of the Lamb, Jesus Christ (John 1:29; 1 Pet 1:18-19)! The rituals given to the church are to serve to remind us always of Jesus Christ, crucified and raised! Jesus said, "Do this in remembrance of me" (1 Cor 11:24). We sing about the cross, we preach the cross, we see it in baptism and celebrate it in the Lord’s Supper. Rituals do not save us. But when God-given rituals flow out of repentant, believing hearts, offering love and thanks to God, they become the demonstrations of our obedience and remembrance.
Just as God paused the story in Exodus to preach to his people of their remembrance of his salvation through the lamb's blood, so believers in Christ are a people of the Lamb. We hear the gospel before we believe. We celebrate - and cherish and proclaim and remember the gospel through rituals - after we have believed. Even in heaven we will be singing of the Lamb that was slain (Rev 5:9)! This gospel is always sweet to us. This is who we are! The Lamb will never be forgotten!
Who his love will not remember?
Who can cease to sing his praise?
He can never be forgotten
Throughout heaven’s eternal days!
(Here is Love Vast as the Ocean, by Rees, Williams and Lowry)