Substitution is the key to the Passion narrative. Jesus Christ died at the feast of Passover which remembered the sacrifice of a lamb whose death enabled God to spare the firstborn of each family. John the Baptist had declared Jesus to be 'the Lamb of God who takes away the sins of the world'. The innocent Jesus was substituted for the guilty Barabbas, and the bystander Simon was the substitute to carry the crosspiece on which Jesus would be nailed.
 
Substitution is a crucial theme in the Bible; it makes God's grace full of justice and not sentimental. The first substitution was when God made clothing from animal skins to cover Adam and Eve: the life of the animals to cover the shame of their sin (Genesis 3:21). The sacrifice of a ram substituted for the death of Abraham's son, Isaac (Genesis 22:1-16). All the burnt offerings of animals in the Law of Moses substituted for the death of sinful people (Leviticus 1:4).
 
In a way, Simon became a representative of the sinful human race. He thought he was not involved with Jesus, but the Roman soldiers forced him to be involved. Simon carried the cross which Jesus would be nailed to; and yet it was for Simon's sins (as well as the sins of everybody in the world) that He died (1 John 2:2). The principle of substitutionary atonement also prevents us from arrogance, thinking that we can be good enough for God without His grace. The truth is that we are incapable of getting ourselves right with God – which is why Jesus chose to die.
 
The substitution of Jesus, in place of us, rebukes our pride because if even some of us could get to heaven by our goodness then Jesus would have died in vain. It should also stir our gratitude that He willingly accepted the punishment which should have been ours. We can only imagine what Simon was thinking as he carried the cross up the hill – would he be crucified? Perhaps all of his life flashed before his mind and he realised that there would be justice in his crucifixion. And then the relief to have the ropes cut at the top of the hill, releasing him from his burden, in time for Jesus to be laid on it and the nails. How glad he must have been that Jesus died for him. Are you?