A Quote by Lao Tzu on secret and the light

Thus the Master is available to all people
and doesn't reject anyone.
He is ready to use all situations
and doesn't waste anything.
This is called embodying the light.
What is a good man but a bad man's teacher?
What is a bad man but a good man's job?
If you don't understand this, you will get lost,
however intelligent you are.
It is the great secret.