> Do you believe instrinsic nature is capable of changing spontaneously over time? If not, then it's essentially hard-coded by god at creation, meaning that god is responsible for the way that soul will function. If god makes a soul with a bad intrinsic nature, it is his fault when that soul does bad things. Likewise, if I create a robot that's evil, it would be my fault when it went hay-wire and started killing people (as they all do).

Or when it starts pushing people down the stairs.

The early twentieth century produced a wealth of German Christian existentialist philosophical theologians (I bet you wish you had a title like that). They are just about the most complicated and confusing theologians this side of good ol' St. Anselm, but they get at what you're describing - the idea that man has a fundamental nature, but that that can change over time. I'm a bit rusty on my twentieth-century German Christian existentialist philosophical theology at the moment, but I'll read up on it a bit and try to bring back some better ideas.

Suffice to say that if you believe that fundamental natures can change, you're not alone. In fact, you're in good company - you can go hang out with Karl Barth, Dietrich Boenhoeffer, and Paul Tillich.