Penal substitutionary atonement is difficult to understand, in part because we fail to conceive of the parties involved properly. Matters are complicated when the likes of N.T. Wright hyperbolically refer to “justification” in the traditional sense as a mysterious “gas” that passes through the courtroom. Others imagine God is like a judge who condemns his son to prison because another man stole someone else’s car. If Sam steals Bob’s car, it makes little sense to imprison little Joey, the judge’s son. Many see here “cosmic child abuse.”
However, this is not the biblical picture. Rather, it is not Bob who has been sinned against, but it is God. Ultimately, every single sin ever committed is against God (Ps 51:4). If God, in His infinite mercy and wisdom, decides to take the punishment for the crimes committed against Him, who can object? The analogy of Sam, Bob, and Joey then is faulty. Instead, we should imagine the judge’s own car being stolen. In response, the judge serves the jail sentence instead of Sam, the thief. He does this because he wants to forgive the thief, but he also wants to uphold the law. Serving the sentence is the only way to do both.
Surely this would be unconventional, but who could object to the judge’s actions? Some, to be sure, would scoff at him but is he not perfectly within his rights? The car belongs to him and him alone, and no one has more say in terms of the resolution of the matter than he does. Furthermore, he has been given the authority—and solemn responsibility—to arbitrate in matters of theft. Therefore, he not only has the right to make a legal decision as a judge but also to absorb the repercussion as the car owner.
In a similar, yet much more profound, way, God owns the world. The car owner did not create the car; he merely bought it. But even if he creates the car himself, he does not create the materials from which it is made. Only God creates ex nihilo; therefore, His ownership is necessarily in a higher category than ours. Furthermore, God Himself is the law-code, whereas the judge merely upholds the law-code. It is by God’s holiness and perfection that all moral judgments are made. Even God Himself does not arbitrarily decide what is good and what is evil. Instead, He exists as the infinite manifestation of the Good.
Even if God were to want to call good evil and evil good (to speak in human terms), He could not because He cannot change. He reserves the absolute right to make determinations regarding justice. The human judge is limited by the law of man proximately and the law of God ultimately, but God is only limited by His own infinite goodness. So, if He decides that it is just to take on the punishment required by the sins committed against Him, who could object to His being willing to do so? Does the murderer shout against the father who forgives him for killing his son? What could the murderer possibly say to that father? Is it not the height of foolishness and pride to say, “You cannot forgive me. Your judgment is unsound!”
We do the same when we question God’s desire and ability to take the punishment for our sins upon Himself. We question this firstly because we fail to remember that our sins against man are ultimately against Him. Secondly, we forget that upholding absolute justice is part of God’s essential nature. The judge could “just forgive,” but that neglects the need for justice. If the judge is more just by serving the sentence himself and therefore forgiving and upholding the law, how much more is this the case with God?