The significance of the serpent in the story of Adam and Eve lies in its representation of temptation and the loss of innocence. The serpent, often viewed as an embodiment of evil, convinces Eve to eat from the Tree of Knowledge, leading to the couple's expulsion from the Garden of Eden. This act symbolizes the transition from a state of purity to one of knowledge and choice, reflecting humanity's ongoing struggle with moral dilemmas. The serpent's role highlights themes of free will, consequences, and the complexity of human nature.