A Course in Miracles

I was centering this morning on my porcelin throne, practicing heavy breathing and meditation while reading my one of my favorite authors. This is what she said in A Return To Love: Reflections on the Principles of A COURSE IN MIRACLES
‘our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond all measure. It is our light, not our darkness, that frightens us the most.’ We ask ourselves, Who am I to be brilliant, gorgeous, talented, famous? 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 people won’t feel insecure around you. We are all meant to shine, as children do. We were born to make manifest the glory of God that is within us. It’s not just 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. And as we’re liberated from our own fear, our presence automatically liberates others. (190,191, ) (Marianne Williamson)

And then I realized: I heard something similar in my I-pod earlier when taking a reflective walk from a Rob Bell podcast:

There is a greatness [in mankind]. The writer here [of Psalm 8] uses the word “glory and honor” that resides in every single human being. Fragile and yet filled with the potential for glory and honor. I love how Nelson Mandela puts it in one of his writings. He says, “Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness, that most frightens us.”
And then he concludes by saying, “Your playing small doesn’t serve the world. We were born to manifest the glory—put on display, to show—the glory of God that is within us.” He says, “you may be a dirt clod, but there is greatness and power and glory that resides in every single human being.”

I am confused, did Marianne Williamson write this and then Nelson Mandela Plagerized it before Rob Bell quoted it? Regardless, it all sounds so cool and so biblical that greatness and honor reside in me. I can't wait to have the glory of the holy one reside in me. Until then, I guess it is okay to have my own light shine in me. I don't want to play small at the shepherds crook!
What do you think?