Light and darkness

Light and darkness;
Are they twin brothers or sisters?
So close they are together;
If you see one, close is the other;
Some people live in abundance;
While others bring light,
Others bring darkness;
While some people give light,
Some people bring darkness;
While some people are light;
Some people are darkness;
After so many years on earth,
What have you brought?
Darkness or light?
My inner voice says light.
What do you like to be?
Darkness or light.