Where do the gospels equate the "life" given to the human body by the soul with the capacity to choose right or wrong? If I'm not mistaken, St. Paul clasifies this in a third category apart from soul and body: the mind.
As far as I know, Paul refers at times to body, soul and spirit. Perhaps "spirit" refers to the indwelling Spirit.
Regardless, through reason we know that the human being is a compound substance of matter (body) and form (soul). (Grace would represent an accidental property of the soul). The human being is an organic unity. The soul is the organizing principle of the body, or in Aristotle's philosophy, the principle of act, whereas the matter upon which the soul operates is the body. Matter refers to potency and is the principle of individuation.