Allow me to put this out there for your edification:
When I go into a restaurant, the waitress who brings me my meal, the cook in the back who prepared it, the delivery men, the wholesalers, the workers in the food-processing factories, the butchers, the farmers, the ranchers, and everyone else in the economic food chain are all being used by God to “give me this day my daily bread.”
This is the doctrine of vocation. God works through people, in their ordinary stations of life to which He has called them, to care for His creation. In this way, He cares for everyone—Christian and non-Christian—whom He has given life.
Luther puts it even more strongly: Vocations are “masks of God.” On the surface, we see an ordinary human face—our mother, the doctor, the teacher, the waitress, our pastor—but, beneath the appearances, God is ministering to us through them. God is hidden in human vocations.
The other side of the coin is that God is hidden in us. When we live out our callings—as spouses, parents, children, employers, employees, citizens, and the rest—God is working through us. Even when we do not realize it, when we fulfill our callings, we too are masks of God.
–Gene Edward Veith, “The Masks of God”
The idea here is that everyone who does his/her job in the way that he/she is supposed to is being used by God to minister to others. This is the gist of Luther’s doctrine of vocation.