Here is most of the conclusion of a paper I am delivering at this symposium, which is titled "Evolutionary Psychology and Romans 5-7: The 'Slavery to Sin' in Human Nature":
In Luke 15, Jesus asks his audience of sheepherders, those close to the land, a question: “Which one of you, having a hundred sheep and losing one of them, does not leave the ninety-nine in the wilderness and go after the one that is lost until he finds it?” In his appeal to their own sense of selflessness in order to speak of God’s mercy toward the 1 lost sheep, Jesus draws on the experience of ordinary people and their common experience in order to interpret the tradition’s view
of salvation as it was understood through the Jewish scriptures. The goal is to speak of God, not as an agent whose intentions are reducible to human forms of pastoral activity, but as an agent whose intentions are analogously understood from the most selfless example of love within the available frame of ordered desires of human living.
The idea here is that sheepherding is a livelihood that meets a set of self-interested desires that is the expression of human nature as this is given particular emphasis by evolutionary psychology in its determination that our interests are preset according to genetic proximity or perceptions of reciprocal exchange that assist our status. Yet, from within the set of tasks that a given livelihood such as this one implies, opportunities exist to offer mercy that would seem to contravene rational self-interest, notably in a case such as this where the pursuit of one sheep puts the herder at risk along with the herd. The point here is that Jesus himself accepts the limits and finitude of human existence yet sees within those limits the episodes of natural living in order to speak of God’s ordered love and God’s inordinate justice.
The parable of the lost sheep affirms the idea that Jesus is concerned for the salvation of the individual. Our natural and cultural environments incline us to sinful behavior in the ways already spelled out, but even within the limits of those inclinations, Jesus manages to identify the kind of activity that suggests the exceptional concern God has for us. If sin is natural, it is also possible to see – in natural terms – the possibility of supernatural love that is a greater power than the sinful power that has befallen nature. A theological interpretation of Romans 5-7 ought not to downplay the genuine paradoxes or contradictions that lie both within human nature and between nature and God. Sin is real and it is not simply a function of the will.
The modern tendency to see a narrative of progress in human affairs is both contradicted by the New Testament and evolutionary psychology, though it is a narrative that has a powerful hold on the western imagination, in part because it is inspired by the possibility of redemption from falleness. This narrative of progress is contradicted by our evolutionary nature, since a pattern of predictable partiality in human affairs exists by human beings toward kin and toward those with whom we are engaged in reciprocal economic or social arrangements. Human nature is also irregularly distorted by inclinations toward addiction, compulsion, anxiety, hyperactivity that interact with a variety of vices that result in behavior that ill befits the body as it was created It is also contradicted by Christ, whose offer of freedom is a final ‘no’, as Barth said, to a purely natural religious reconstruction of human desire. The ‘ordered desire’ of Augustine’s City of God is consistent with both a recognition of our fallen state and the eschatological tension that exists between this state and our final destination with God. It is fitting to end with Augustine, because as he was the proponent of the Doctrine of Original Sin, he had a consistent, realistic view of the wretched tendency in human wilfulness to disturb the ordering of desire. A theological interpretation of scripture must also be a faithful, realistic interpretation of the human condition, both in all its natural goodness and its tendency to evil.