The Passover was a foreshadowing of what would happen on a spiritual scale through the death of Jesus.  Punishment was coming on those who would not submit to God and trust in his way and offer of life.  But there was hope to be rescued and redeemed from this punishment and destruction.

A lamb could be killed, and its blood spread over the doorposts of a house.  Blood could cover a family and forgiveness and grace would be offered to them, if they trusted in God’s invitation and followed his commandments.

This lamb was really just a foretaste of the ultimate lamb, whose blood would one day be shed to cover all of humanity.  Jesus is the great passover lamb, and God’s grace and mercy is offered to us when we cover the doorposts of our lives with his blood.

Humanity is deserving of death and punishment… our sins should lead to our destruction as well, but Jesus shed his blood to offer us life instead.