To quote Last Order: You don't need a reason to live.
And to add my own thoughts: If you needed one, you'd stop living without one. But even those who can't find something to justify their existence keep on existing. You don't need to find an excuse for your life, you don't need to see yourself as a part of some greater plan. You don't need to justify your existence. You were born for no particular reason, you might well die for no particular reason, and there's no particular reason for the life you lead inbetween. Life's what you make it. If you need a reason for your life, make one. If you need justification for your existence, justify it. But don't go searching for the answer like somebody else can tell you, or like a slip of paper will magically flutter from the heavens with directions for your course in life.
Unless you are a devout of Darwin's teaching, in which case the meaning of life is to reproduce. So go do that, I hear it's mighty fun.
