Professor Carol Thomas, who taught ancient History at the U of Washington, back in the mid 70s warned us budding historians of a constant danger: “Beware the hardening of the categories.” Popular history tends to speak of ages (e. g. The Gilded Age) and identifiable reasons for events (e.g. Slavery did nor did not cause the American Civil War.) Life is more complex than that. It is hard to divide out one cause, but many things work together. History is more like an ecosystem than a syllogism.
We often tend to divide things that may best be seen together. In Romans 12:2 some commentators want to talk about this verse in the Platonic categories of “internal” and “external” forms. (i.e. Do not be conformed to the changeable fashions of the age, but be changed in your inner life.) Yet it is a comprehensive system of thinking and acting that makes up this “world” or “age”. The “world” is both inside of us and attempting to shape us from the outside.
It is for this reason that the vision of Romans 12:1-2 is not accomplished in a day with a single decision.