What is the Best Trick the Devil Ever Pulled?

Answer 1

Convincing the world he does not exist
or
That radical 360 he did on the Harley.

Answer 2

Convincing the world he didn't exist. From the film The Usual Suspects.

We all know that but do you know where that quote came from? French poet Baudelaire's "Le Joueur généreux"

"Le Joueur généreux

He did not complain in any way about the bad reputation he enjoyed all over the world, assured me that he himself was the person the most interested in the destruction of superstition, and admitted to me that he had only been afraid for his own power one time, and that was the day when he had heard a preacher, more subtle than his colleagues, shout out from the pulpit:

"My dear brothers, never forget, when you hear the progress of enlightenment vaunted, that the devil's best trick is to persuade you that he doesn't exist!"