Call this a public service because you, too, may feel compelled to spread this meme today.
— Life at EY (@EYstaff) December 6, 2013
Well, there's one indisputable fact here, he was an inspiring man. However, that quote isn't his.
[Note: as I was writing this, @EYstaff deleted the tweet. Thank goodness I thought to take a screenshot or we'd have nothing to talk about here!]
The quote is actually a paragraph from “A Return to Love: Reflections on the Principles of a Course in Miracles,” a 1992 book by Marianne Williamson:
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. We ask ourselves, who am I to be brilliant, gorgeous, talented, fabulous? 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 around you. 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.
No one really knows why this quote is attributed to Nelson Mandela. All you need to know is that he didn't say it, so make sure before you post that he said what you're saying he said.
When in doubt, go with this one:
For to be free is not merely to cast off one’s chains, but to live in a way that respects and enhances the freedom of others.
Or, if you really want to impress people, pick a lesser known but equally inspiring quote from the same book (hint hint, EY, you're welcome).