God paid the penalty our sin, we, being worthless without God, unable to offer Him recompense for the sins we’ve committed against Heaven, were given eternal hope when God said, ‘I will do it, I will pay the cost for their sin,’ and came in person, fully incarnate to do so.

All the host of heaven was in awe of His grace and humility, how could God, the Lord of the universe and the King of eternity, deign to step into creation and mix with sinful man, how could perfect purity stand to be around unrighteous sin and the heinous wicked?

I don’t know how but He, so desiring to save us did indeed deign to garb Himself in a servant’s raiment and come down to meet us at our worst.

Why the crucifixion? Christ became sin for us on the cross, the perfect sacrifice approvable to God, to qualify us for Heaven’s destination, wiping away the record of our sin.

Some say it is not just that another pay the penalty of someone else’s crime. Yet Christ really did take on our sin there was no other way, He willingly sacrificed Himself for us, so we could be saved. His offer is a free gift, one need only choose to accept it. But that does not mean it comes without sacrifice on our part as well, for we must forsake sin and unrighteousness and take up our cross daily if we are to be true children of God and accepted at the Father’s table, brothers of Christ who made the cause of the needy their own course.

Of course we fall short and must confess our sins and always seek reconciliation with God when we do wrong, but even though we are far from perfect when we accept God’s offer we become His children and must strive for righteousness at all costs— see Dr Michael Brown’s excellent book on holiness for more on holy living (‘Go and Sin not More: a Call to Holy Living’)— so when we accept what Christ did on the cross we must follow His commandments and the cost of that is our old way of living. Indeed Christ said, ‘why do you call me, Lord, Lord, and not do what I tell you?’ (Luke 6: 46)

Recall the parable of the tower, one must count the cost of building the structure, in the same way we must have to work out what is the cost of being a disciple of Christ. Christ’s sacrifice is enough, but we must be willing to take pains in order to please Him, so we do not find ourselves disqualified.

So while someone else is taking on the charges against the criminal (i.e. Christ) and releasing him from sentence, that criminal has to be willing to be rehabilitated– a transformation of character– because there is a stipulation, the criminal must now forgo to be a criminal any longer, the onus is on him to change his ways, else how can the criminal remain forgiven if he does not repent of doing crime?

If the criminal refuses to change he will have to pay the penalty for his crime despite that there was someone willing to pay it for him. Of course the parable of the prodigal son explains God is always more than willing to have us back when we turn from sin.