A metaphor might help us make this more concrete. Imagine that you are standing near an airplane.  That plane can do something that you cannot do yourself.  You are held down by the law of gravity and no matter how hard you flap your arms, you cannot fly.  The plane, on the other hand, was created to fly.  You may have a great desire to fly.  You may know everything about planes.  You can stand really near it or even lie on top of it, but it can’t make you fly.  That plane, when it takes off, will not take you with it—unless you are in it.