The Garden of Eden

It is a historical parable--like when Suetonius tells his stories, or Plutarch--of man coming into judgment and knowing right from wrong. The serpent is Satan, the deceiver, tempting Adam and Eve in their innocence--before they know how to tell right from wrong--and causing them to commit sin, where the sin is coming into the knowledge of sin. The Nakedness is Adam and Eve without the knowledge of sin, so they don't know it's shameful yet, until they eat from the fruit, and then they know why sin is sin. That's ultimately the core of why God has to judge the world, too, is that we corrupted it through our knowledge, and why Christ says "Judge not lest you be judged." Because judgment is the first sin humans acquired, from eating the fruit.