If I'm not mistaken, this is Catholic rhetoric. For example, ordained priests are "called" to the Church. The Protestant Reformation brought about Calvinist reorientations in belief, and the doctrine of predestination superseded intercessory prayer (i.e. Catholics praying for forgiveness of individual sins > Protestants were either saved or damned by God from the day we were born, but there's no way to know which path we've been set on, so the best we can do for comfort is to look for signs of our salvation, e.g. Good fortune). God would not "call" to a Calvinist directly, but predestination would have settled the path for the believer. With the Reformation comes Capitalism and Protestant "work ethic" (see Max Weber on this), so I assume the "calling" to the Church was funneled into new emphases on capitalist callings, where the work Protestants were "called" to do served as one of the only sources for evidence of salvation (hard work > good fortune= potentially saved) and the humble and modest labor they performed became the (contradictory, I know) only way to assuage fear of damnation, "work ethic" serving as a testament to walking the righteous path to salvation.