Writing about something with the purpose of proving or disproving, clarifying, reviewing, or judging its merits is writing intended to "inform" since it seeks the truth. Of course "inform" and "persuade" go hand-in-hand quite frequently.
Its comparing your body to the car, if you take care of it you should take care of yourself. Your food to gas Your organs to the parts in a car Your pride for your body to the pride of your car