Explaining security is really hard, but sometimes a sports analogy helps. Here’s an appropriate sports analogy for security.
Imagine you’re playing a sport. The sport doesn’t matter. What matters is you’re playing, and so is the opponent, and you have to follow the rules while they don’t. But you still have to prevent them from scoring.
But it’s more complicated than that. Imagine there’s another game going on, either adjacent to the field or within the field. That’s the business. Whatever you do can’t interfere with that second game, and you also have to keep your cheating opponent from interfering with that second game. And your success at preventing interference with that second game is how you’re going to be judged.