God could have chosen to redeem the Israelites any way He wanted, but he used 10 plagues, each specifically geared to confront and essentially dethrone an Egyptian deity. The final plague was the death of all the firstborn in the land, and the only way death would pass over them is if they offered the sacrifice of an unblemished lamb, putting the blood of the lamb on their doorposts and lintels. Exodus is symbolic of a much bigger deliverance that Jesus, the Lamb of God, has provided. We have all sinned, and sin brings death. Jesus sacrificed Himself in our place, shedding His blood so death would pass over us, bringing freedom from Satan and sin, if we would only put our trust in the finished work of Christ.
See a representation of the significance of Passover and the sacrifice Jesus made for us in Exodus: A Passover Story.