Why was it necessary for Jesus to be born as a human being and die on the cross? Surely an all powerful, all knowing, loving God could devise a simpler, less costly way to allow us to enter heaven? Perhaps he could just have left a checklist for us to complete here on earth to be rubber stamped at the pearly gates and exchanged for a heavenly entry visa. Maybe he could simply just forgive our sin and waive us straight through, no questions asked. What is Penal Substitution and why is it vital that we understand and defend this truth? Let's start by reminding ourselves about what we learned of God's character and humanity's status before God and then celebrate God's incredible solution.
God says he is truthful
"God is not a man that he should lie, nor a son of man, that he should change his mind" [Numbers 23:19]. Therefore when God said to Adam "you must not eat from the tree of the knowledge of good and evil for when you eat of it you will surely die" [Genesis 2:17] he had to introduce death as the "wages of sin" [Romans 6:23] when Adam and Eve disobeyed His command. So if we stand back and examine the consequences of God simply forgiving sin to remove death, then we realise that this would make God a liar and Satan the truthful one, for it was Satan who said "you will not surely die" [Genesis 3:4].
God says he is angry at sin
"The wrath of God is being revealed from heaven against all the godlessness and wickedness of men" [Romans 1:18]. This is not just Adam and Eve's problem since "sin entered the world through one man [Adam], and death through sin, and in this way death came to all men, because all sinned" [Romans 5:12]. When God surveys the people of the world in any age he finds "there is no-one righteous, not even one, there is no-one who understands, no-one who seeks God" [Romans 3:10-12]. Just think, it's not just Stalin or Joseph Fritzl who fall into this category it is me, you and even Mother Teresa!
God says he is just
He "will not acquit the guilty" [Deuteronomy 25:1] and "Acquitting the guilty and condemning the innocent - the LORD detests them both" [Proverbs 17:15]. We should find it immensely reassuring that there is never any miscarriage of justice with God, never any trumped up charges or leniency but rather perfect justice - like we all want to see from our police, courts and football referees! We know that "man is destined to die once, and after that to face judgement" [Hebrews 9:27] and this judgement will be fair. Soberingly though, we are incapable of doing good [Romans 3:12] and do not know the way of peace [Romans 3:17]. So without some external intervention, God would rightly and fairly condemn us when he came to judge. If we appreciate this truth, we can see that it is impossible for us to complete a checklist to pass God's judgement and enter into heaven by our own initiative, no matter how inspirited, dedicated or motivated we are.
Mercifully, God himself has intervened
By sending his Son Jesus to die as a Penal Substitute. We learned this means Jesus paid the penalty for sin and bore the anger of God for sin in our place so we don't have to undergo the fair and just judgement and anger from God that our ways deserve. It was not easy for God to do this. To remain faithful to His character; His love, mercy, justice, anger and truthfulness, whilst justifying us who are godless, wicked and incapable of doing good resulted in Jesus being "deeply distressed and troubled" [Mark 14:33] at the prospect of going to the Cross and even asking his Father "if you are willing, take this cup from me [Luke 22:42]".
It is sobering to think that this is the same Jesus who calmed the storm, cast out demons and raised the little girl from the dead with such aplomb. Do we really understand that Jesus' death on the cross was the ONLY way to reconcile us to God? Do we secretly think that we should add something to what Jesus has already accomplished? I've heard it said that it is only once the doctor has diagnosed your condition that you appreciate the offer of medicine. In our case "He was pierced for our transgressions, he was crushed for our iniquities: the punishment that brought us peace was upon him, and by his wounds we are healed...the Lord has laid on him the iniquity of us all" [Isaiah 53:4-6] for "God made him who had no sin to be sin for us so that in him we might become the righteousness of God" [2 Corinthians 5:21].
God's promise goes out into the world today that "whoever calls on the name of the Lord will be saved" [Acts 2:21] and "there is now no condemnation for those who are in Christ Jesus" [Romans 8:1].
"Thanks be to God for His indescribable gift!" [2 Corinthians 9:15].