In the story of the Passover and the Exodus, we have the foundational OT revelation of God's salvation. In the story we learn that the Israelites deserved death no less than the Egyptians, that God provided for their deliverance from death through a sacrificial lamb and that the point of this deliverance was that the the people might leave the bondage of Egypt and serve the Lord. For us Christ is the sacrificial lamb by whom God delivers us from death so that we might be released from our bondage to sin to worship and serve the Lord. The celebration of the Passover is fulfilled in the Lord's Supper.
Read Exodus 12:1-28