Every man is an actor in a play, in which God has assigned the parts; it is our duty to perform our part worthily, whatever it may be.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“In general, in common with other Stoics, he despises pleasure, but there is a kind of happiness that is not to be despised. “Athens is beautiful. Yes, but happiness is far more beautiful—freedom from passion and disturbance, the sense that your affairs depend on no one” (p. 428) . Every man is an actor in a play, in which God has assigned the parts; it is our duty to perform our part worthily, whatever it may be. There is great sincerity and simplicity in the writings which record the teaching of Epictetus. (They are written down from notes by his pupil Arrian.) His morality is lofty and unworldly; in a situation in which a man’s main duty is to resist tyrannical power, it would be difficult to find anything more helpful.” source