What do we do with food that is rotten? Of course we throw it. What of appliances that break down? In our culture we throw them, even though they might be repaired or usefully recycled. But what do we do when people are bad - do we simply discard them?
The Exodus story is one of a whole people rescued out of slavery. Yet at first they could not leave, with an ever increasing battle of rhetoric between Moses and Pharaoh. Pharaoh's blocking of their path led to nuisance, destruction of property and of livestock as the upping of the ante continued. It is all characterised by the hard heart of Pharaoh, that eventually led to all of the firstborn of Egypt having to die before he finally changed his mind.
In parallel with this God gives the Israelites some curious instructions. They are to hold a family feast with a slaughtered lamb, smear blood on the doorposts, and stay indoors while death occurred across the land.
So how do we make sense of all this? Let us un-pick some of the different aspects.
First the roast meal is for the extended family, and is about togetherness, fellowship, and covenant. It is also about a desire to be together with God, in His presence. It is therefore about having a soft heart. Second is to realise that to truly have a soft heart then something in us must die - the wrong things, the bad attitudes, the rot in our lives all needs to go.
Third is to understand the cultural significance of the blood as a sign of life. Blood poured out therefore means that life has been spent, and the doorpost smear signifies life spent here, acting as a witness. Finally another cultural point is the firstborn male, which represents continuing life of you and your family. He is your prodigy, the extension of you. To lose your firstborn, therefore, is akin to loss of continuing life, like a cutting off of your family.
In summary we have fellowship, hard versus soft heart, the need to remove the hard-heartedness in us, life spent, and life cut off.
Now what if we realise just how hard-hearted we are? What if we strip out of ourselves the bad, but find that our hardness runs deeper and deeper? Can we cut out our whole heart? Well no, of course, for we would die. Yet what if such a radical heart replacement was the only way to achieve the soft heart that then welcomes the presence of God?
Yet God knows our predicament and can devise a way - a kind of substitution. A way that instead of us dying, a death actually occurs elsewhere and in the process we can then be free. Could it be that killing the lamb and enjoying it as a family roast is in fact a death instead of our own, so we can now have friendship with God? If this could be achieved then of course you would smear some of the lamb's blood on your door-post, to show the death has occurred here, we now want to be free.
But return again to the firstborn, the dying of which signifies future life lost. For Egypt it was all their firstborns from greatest to least - in other words a whole generation lost. Through this occurrence Pharaoh changed his mind and let the Israelites go, escaping their oppression. We see therefore that the loss of a generation enabled freedom to a whole people race.
Yet big though this was, it was really just the film trailer, the Hollywood teaser. For in time God would do something far greater, with universal significance. For a day would come when God would send Himself, a person of the God-head who relates as a son relates to a father. This person would be born a human, and therefore effectively be God's firstborn son here on earth. This man would live a totally soft-hearted life, inclined to God all the way through.
Yet his own fellow humanity would turn on him, would put him on a cross to die - his blood spilt and his life spent. This was God's way, this was God's grand swap, a substitution: that somehow the life of the of this one firstborn would be lost to enable the whole people to be restored, to be free to have friendship with God once again.
This is our faith - that any who would welcome Jesus, who would realise that their own hard-hearted life must die, would discover that it can be renewed with a soft heart in following Jesus. This new life is possible because of the action of the one - like a lamb slaughtered and blood spent, like a firstborn lost in our place. If we could somehow wear a smear of his blood ... then we certainly would - to show that our trust is rooted in Him who died. A sign so that on a night when God finally really has to sweep away absolutely ALL that is bad, we can be passed over, kept, ready for up-cycling, becoming redeemed and restored to how we should be.