Ever since I first learned about different atonement theories, I have been open to the positive points of most of them, especially ransom, satisfaction, and substitution. And that was mainly because I didn’t feel that they’re mutually exclusive. In ad Diognetus 9:2-5, I found a way to articulate this synthesis.
God did not hate us, or drive us away, or bear us ill will. Rather, he was long-suffering and forbearing. In his mercy, he took up the burden of our sins. He gave up his own Son as a ransom for us – the holy one for the unjust, the innocent for the guilty, the righteous one for the unrighteous, the incorruptible for the corruptible, the immortal for the mortal. For what else could cover our sins except his righteousness? In whom could we, lawless and impious as we were, be made righteous except in the Son of God alone? O sweetest exchange! O unfathomable work of God! O blessings beyond all expectation! The sinfulness of many is hidden in the Righteous One, while the righteousness of the One justifies sinners. *
That “God did not hate us” refers to God’s enduring love for us. That “he took up the burden of our sins,” and we were “made righteous… in the Son of God,” and “the righteousness of the One justifies sinners” all imply the substitutionary aspects of atonement. “His own Son as a ransom for us” is obviously referring to the ransom aspect. Additionally, referring to the human state of lawlessness and impiety indicate the sense in which we formerly belonged to Satan. And finally, the phrase “the sinfulness of many is hidden in the Righteous One” provokes the same imagery that Anselm utilizes when he describes Jesus as having made satisfaction for our sins.
Thus, I would sum up these truths under the title of Exchange theory. We exchange our sins for Christ’s righteousness. We exchange darkness for light, the world for God, death for life. Jesus ransoms us from the devil’s reign to his own reign, inasmuch as all sinners belong to the devil. It’s a radical change of allegiance beyond even our natural ability to make, as ad Diognetus 9:6 affirms. Though to say how Christ works this atonement for us is beyond the scope of what I’m trying to summarize here. The exchange is intended to be a description of what happens, not how it happens. What = atonement theology, how = Soteriology, which is far more complicated. And I’ve got three books lined up to read about justification before I can get too deep into that!
* Cyril C. Richardson, ed., “Letter to Diognetus,” Early Christian Fathers, pp 220-221, emphasis added.