Let's focus on what the serpent does: he deceives. More importantly, he gets Eve to question God. The serpent says things like: "Did God actually say..." and “You will not surely die. For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.” Questioning God is not bad (look at the Psalms if you doubt this), but the serpent gets Eve to doubt that she heard God correctly. He gets her to doubt that God has her best interest in mind--that He is keeping something good from her. He gets her to question God's relationship with her.
This is Satan's tactic: to get us to believe the lies. They're not outright "black is white" kind of lies. They're subtle. They're intended to get us to question God, to question ourselves, in ways that our relationships will no longer be as whole as they once were. "You're not good enough." "A little sin won't hurt anyone." "God doesn't want you to be happy--that's why nothing is going right." If it makes you happy, do it." "Go ahead, you deserve it."
After hearing those voices again and again, the sound of God's voice slowly fades. We forget His words. "I have chosen you." "You were created for good works." "I have a plan for you." "The wages of sin is separation from me." "You are fearfully and wonderfully made."
In the waiting of Advent, it is important to refocus our ears to hearing Gods words and tuning out the devil's deceit. In the silence, in the listening, may we "be still and know that [He] is God."