Genesis 3:5 - “For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.”
Satan didn’t lie about this. God confirms it:
Genesis 3:22 - Then the Lord God said, “Behold, the man has become like one of us in knowing good and evil.”
Having direct, experiential knowledge of evil is not enlightenment as Satan pitched it and as we’re tempted with today. Evil is ever and always destruction to our souls. Oh, God, deliver us from evil.