In the fight between right and wrong, one person can make a difference.
As a "peculiar people," we're charged to make a difference in the world--but the world is so troubled that it’s sometimes easy for me to get discouraged. “Even if I do what I feel is right,” I often think, “what difference would it make?” With the wrong mindset, even good things like giving what I can to the poor or being kind to those around me seem painfully insignificant. After all, I’m not going to solve world hunger, and I’m not going to stop unkindness. So why even bother?
Perhaps Snape thought the same thing on occasion. He’d witnessed the powers of evil firsthand, and they were fearsome and strong. Was there any point in fighting it? Right up until Snape's death, it seemed as though those battling for right were simply prolonging the inevitable—but with his final acts, he turned the tables in favor of good. The courage of Professor Severus Snape set in motion a chain of events that ultimately led to the collapse of Voldemort’s power and the redemption of the wizarding world.
Not bad for a peculiar kid from Slytherin.