XIV. (13) Their fanciful division of the Scriptures rejected.
In the thirteenth place comes their assertion that the whole body of the canonical Scriptures is to be accepted, under the names of the patriarchs: because those twelve virtues which work the reformation of the inner man are pointed out in their names, and without this knowledge no soul can effect its reformation, and return to that substance from which it came forth. But this wicked delusion the Christian wisdom holds in disdain, for it knows that the nature of the true Godhead is inviolable and immutable: but the soul, whether living in the body or separated from the body, is subject to many passions: whereas, of course, if it were part of the divine essence, no adversity could happen to it. And therefore there is no comparison between them: One is the Creator, the other is the creature. For He is always the same, and suffers no change: but the soul is changeable, even if not changed, because its power of not changing is a gift, and not a property.
Source: Letters (New Advent)