My religious tradition views Adam and Eve as created with perfect human natures. After their first sin, their natures became “fallen” and prone to sin, and this fallen nature was passed along to all of their descendants, making all of us prone to sin as well. In Jesus’ sacrifice we are forgiven our sins and promised to be restored to a perfect, unfallen nature when this life is over.
In the post What Does Original Sin Mean in the Light of Modern Science? Jason Rosenhouse discusses how evolutionary theory gives a different explanation of our “fallen” natures: primates are species on a trajectory from “animal” to “rational” and we have a lot of dark impulses to overcome when our conscience and our instincts are in conflict. Concerning whether the idea of original sin should be reworked or discarded, he concludes:
In science, it is fairly common to face the following situation: A theory works pretty well and explains a fair amount of data. But then some anomalies arise. Do we need to discard the theory completely, or is it just a matter of fine-tuning a few details? That is not the case with original sin. It is not as though we used to have really good reasons for thinking it is a valid and useful notion, but then modern science came along to provide a few distressing anomalies. Actually all we ever had was an ancient, Biblical account that told a pretty clear story about human sinfulness and its affect on the world. There was never any particular reason to think that story was true, and science now shows it to be completely false. But instead of throwing the idea of original sin straight in the garbage where it belongs, a lot of really smart people tie themselves into knots summoning forth strained reinterpretations of the doctrine. It is beyond comprehension to me that anyone could think this is a valuable use of time, or that our knowledge or understanding of the human condition are advanced, in even the slightest way, by such investigations.
If original sin is discarded, it would still remain true that we are prone to sin and that Jesus lived a perfect life. The Christus Victor model of atonement could still apply.