I am forcing myself to keep my comments brief. From the standpoint of the Lutheran Confessions, you are right (and likely have little need for my confirmation) to say there is an intimate tie between our confession concerning OS and our understanding of the Gospel. Melanchthon, himself, testifies to this in the Apology of the Augsburg Confession: "Knowledge of original sin is a necessity. For we cannot know the magnitude of Christ’s grace unless we first recognize our malady. [The German translation adds, “As Christ says in Matthew 9:12 and Mark 2:17: “Those who are well have no need of a physician.”] The entire righteousness of the human creature is sheer hypocrisy before God unless we admit that by nature the heart is lacking love, fear, and trust in God. Thus the prophet says [Jer. 31:19], ‘And after I was discovered, I struck my thigh.’ Again [Ps. 116:11], ‘I said in my consideration, ‘Everyone is a liar,’’ that is, they do not think rightly about God.” (Ap.II.33-34) Should the foundation of our understanding of OS change, so, too, would our understanding of Christ and his work.
I offer with transparency, though with little-to-no qualification here, that I do not think Hart has dealt such a fatal blow to the doctrine of OS, so much as he has questioned an oft-unquestioned (in more symbolic circles, at least) interpretation of Rom. 5:12ff. A question demanding critical reflection. There was a great deal more I wanted to say about God electing, universal atonement, exegesis, The Bondage of the Will, etc. but my psychology demands I limit myself from the internet sometimes. Instead, I will offer a suggested reading for counterpoint - or at least a little push-back - to the exegesis of Rom. 5:12ff. from the article you posted. I’m recommending an article from (of all sources) Calvin Theological Journal. The article is by Peter J. Leithart and is titled: “Adam, Moses, and Jesus: a reading of Romans 5:12-14.” As to its availability, access to ATLA or Calvin Theological Journal may be the only means. If I have the time, I’ll try to read it again and give a sketch of his argument for those unable to access.
A Spirit-stirred Adventide to you and yours,
J
(I indulged myself and included some closing remarks by Cameron MacKenzie in his The Origins and Consequences of Original Sin in Luther’s Bondage of the Will:
"But why the world is the way it is, why God permitted Adam to sin, why God transmitted that sin through all generations, and why He continues to let Adam’s offspring suffer its horrible consequences, we do not know, nor should we seek to know. Without making very clear the grounds of his optimism, Luther believes that by the light of glory, we will all understand the justice of God in these matters even if at present we do not; nevertheless here and now, our proper response is simply to believe in the righteous justice of God.
“Humility in the face of divine mysteries is always the right course, and for Christians, the Gospel—God’s revealed will—is always the answer to the horrors of the human condition. Nevertheless, in this work, The Bondage of the Will, Luther forces us to face these horrors and to realize that at their center is a hidden God who in a strange way wills them, including our sin and death. Original sin is certainly ours, for prior to faith we willingly embrace all that it entails and even after faith, we are always wrestling with its aftereffects in our lives. However, nothing that we are or do changes the fact that God is always in charge. This may make us uncomfortable when we are discussing sin, but it is absolutely necessary for believing the Gospel.”)