Serpent spoken of in Genesis is not a snake.  It is a Nahash.  A creature that is fiery and that has powers of enchantment.  It originally had wings, but then God cursed him and took away his wings, saying: Upon thy belly shalt thou go.(Genesis 3:4)

Nowhere in Genesis does it say the Nahash is an animal or a devil.   Nowhere in Genesis does the Nahash lie.  He that Adam and Eve would not die the day she ate the fruit of the Tree of Knowledge of Good and Evil and that they would become as gods, knowing good and evil.  She did not die and even God acknowledged: Behold the man has become as one of us, to know good and evil. (Genesis 3:22)

The Nahash is the seraph, the kundalini, the evolutionary force in man that moves him to evolve, grow and constantly improve himself and gain power over his environment..