Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive.
Your dreams must be such that only God can make them occur. Dreams are to take you to a point where only God can rescue you, and if they are dashed, a part of you will die. And if that part of you dies, only God can bring it back to life. Your dreams must take you into danger.