Actually, who are you not to be?
You are a child of God.
Your playing small doesn’t serve the world.
There’s nothing enlightened about shrinking so that
 other people won’t feel insecure about you.

We were born to make manifest the glory of God that is within us.
It’s not just in some of us, it’s in everyone.
And as we let our own light shine,
we unconsciously give other people permission to do the same.
As we are liberated from our own fear,
our presence automatically liberates others.
 

Marianne Williamson,
from her 1992 book, "Return to Love" (p. 165)