here's the wikipedia definition of the protestant work ethic. It's basically Rand. Not a perfect definition, but I hope you see my point.
It is argued that Protestants, beginning with Martin Luther, had reconceptualised worldly work as a duty which benefits both the individual and society as a whole. Thus, the Catholic idea of good works was transformed into an obligation to consistently work diligently as a sign of grace...
...hard work and frugality, as well as social success and wealth, were thought to be two important consequences of being one of the elect; thus, Protestants were thus attracted to these qualities and supposed to strive for reaching them.