I would also encourage you to read these quotations from Augustine, John Chrysostom, Anselm, Thomas Aquinas, Luther, and Lewis, all of which cite the injustice of Jesus' death as central to the atonement mechanism. But this is in contradiction to penal substitution, which claims that Jesus' death was just/deserved.
Augustine states that the cross is where the devil lost his right of death over humanity because he unjustly killed the Son of God in whom there was no sin:
It is not then difficult to see that the
devil was conquered, when he who was slain by Him rose again. It is something more, and more profound of comprehension, to see that the
devil was conquered when he thought himself to have conquered, that is, when Christ was slain. For then that blood, since it was His who had no
sin at all, was poured out for the remission of our
sins;
that, because the devil deservedly held those whom, as guilty of sin, he bound by the condition of death, he might deservedly loose them through Him, whom, as guilty of no sin, the punishment of death undeservedly affected. The strong man was conquered by this righteousness, and bound with this chain, that his vessels might be spoiled, which with himself and his
angels had been vessels of
wrath while with him, and might be turned into vessels of mercy.
[1]
John Chrysostom agrees,
“It is as if Christ said, ‘Now shall a trial be held, and a judgment be pronounced. How and in what manner? He (the devil) smote the first man (Adam), because he found him guilty of sin; for it was through sin that death entered in. But he did not find any sin in Me; wherefore then did he fall on Me and give Me up to the power of death? . . . How is the world now judged in Me?’ It is as if it were said to the devil at a seat of judgment: ‘Thou didst smite them all, because thou didst find them guilty of sin; wherefore then didst thou smite Christ? Is it not evident that thou didst this wrongfully? Therefore the whole world shall become righteous through Him.’”
[2]
Anselm of Canterbury says this aspect is part of the popular view of atonement in his day. It is justice that sets Jesus free from death, not justice that kills Jesus:
“That God, in order to set mankind free, was obliged to act against the devil by justice rather than mighty power. We reason that thus the devil, having killed Him in whom there was no guilt deserving death and who was God, would justly lose the power which he used to have over sinners.”[3]
Thomas Aquinas, in the 13th century, affirms this as well:
“
Christ's Passion delivered us from the
devil, inasmuch as in
Christ's Passion [the devil] exceeded the limit of power assigned him by
God, by conspiring to bring about
Christ's death, Who, being sinless, did not deserve to die. Hence
Augustine says (De Trin. xiii, cap. xiv): "The
devil was vanquished by
Christ's justice: because, while discovering in Him nothing deserving of death, nevertheless he slew Him. And it is certainly just that the debtors whom he held captive should be set at liberty since they
believed in Him whom the
devil slew, though He was no debtor."
And even Martin Luther applies the loss of rights to the Law rather than the devil:
“Thou hearest that Christ was caught in the bondage in which we all were held, was set under the Law, was a man full of all grace, righteousness, etc., full of life, yea, He was even the Life itself; now comes the Law and casts itself at Him and would deal with Him as with all other men. Christ sees this, lets the tyrant perform his will upon Him, lets the reproach of all guilt fall against Himself as one accursed, yea, bears the name that He Himself is the curse, and goes to suffer for this cause, dies, and is buried. Now, thinks the Law, He is overpowered; but it knew not that it had so grievously mistaken itself, and that it had condemned and throttled the Son of God; and
since it has now judged and condemned Him, who was guiltless and over whom it had no authority, it must in its turn be taken, and see itself made captive and crucified, and lose all its power, and lie under the feet of Him whom it had condemned.”
[4][5]
When our Lord was roaming around Narnia in the form of a giant, magical, not-safe-yet-good lion, he said,
“when a willing victim who had committed no treachery was killed in a traitor’s stead, the Table would crack and Death itself would start working backward.” (it is interesting to think that if we read
The Lion, the Witch, and the Wardrobe through the lens of Penal Substitution, the White Witch would represent God the Father! I highly doubt this was Lewis’ intention in the allegory)
[1] Augustine. De Trinity. Book 13, Chapter 15.
[2] Chrysostom, John.
Homily LXVII. Database online.
Philip Schaff: NPNF1-14. Saint Chrysostom: Homilies on the Gospel of St. John and the Epistle to the Hebrews - Christian Classics Ethereal Library
[3] Anselm,
Why God Became Man. Book 1, Chapter 7. Anselm does not fully agree with this idea, but it is important to not that this was a popular view among Christians in the 11th century.
[4] Luther, Martin.
Works, XXIII., p.709
[5] I am indebted to Gustaf Aulen’s
Christus Victor, for the references to Chrysostom and Luther.