If you are lucky, you will live to see your parents begin to need you in the way you once needed them.
You will feel it most in the small things: lifting a cup of water to your mother’s lips; adjusting the light your father can sleep. Laying a hand on his forehead.
And you will be desperately sad, but also lucky, because each time you do these things, you will remember that they once, so many times, did them for you.  And you will know that you were, and are, loved.
God, too, is a parent.  But God’s biggest tragedy, if one can say such a thing, is that God will never grow weak or old.  God will never need us to do for Him what He once did for us.