Let us set aside hocus-pocus of every stripe, and talk about Soul and Spirit. Soul and Spirit are not the property of religious descriptions of reality: Soul and Spirit are perceived aspects of being that must be accounted for in even secular myth building.
What is the existential nature of the Soul? What is it within us that we discover and then notice as our very own “Soul”? Taking the human animal as we find it, Soul is a haze of potential latent in the human mind. The capacity for love and loathing, for desire and disdain, the inclination to be and not to be, all yearnings to and fro rise from the latent potential which is the Soul. Like a trout rises to the fly or flees a shadow in response to perceived configurations in the field of reality so is the nature of the Soul.
That the Soul does not choose to rise: that it is drawn, and that it does not choose what to find attractive, any awakened awareness will discover for itself.
Spirit is the element of being which determines our response to the voice of the Soul. Everything the Soul is capable of is not attractive to a given Spirit: not every inclination will engage our will. And it is here, in the nature of our willing, that the Spirit displays itself. As an example let’s take sex. It is the soul that is the repository of the sexual inclination, and then it is the Spirit that determines how sex is configured in our lives. And any apparent maturation of the Soul is the result of the Soul consigning itself to the will of an awakening Spirit. This is the story told in the fable of “The Ten Bulls” that we find in Buddhist lore.
So the Soul and the Spirit are arguably experienced as organs of mentation. And mentation here need not be confined to the kind of supposed intentional thinking we find in humans. Unless we are ready to dismiss lower animal behavior as a matrix of tropisms it is obvious that they too posses these organs of mentation. It is certainly obvious that they experience joy and suffering; and if this joy and suffering reduces to tropism, what does that say about human suffering and what does that imply about that in our selves to which we say yes or no? And what is it in the creature that possesses the yes-no imprimatur?
Which brings us to the question of good and evil. The soul is an iridescent haze of potentiality. There is no evil that is not private good. It is all about that to which we say "YES".