The word “vocation” has long received a significant amount of usage in Christian theology. Defining it, however, seems to be a difficult task. This is perhaps the best definition of vocation that I have come across:
“Vocation comes from the Latin vocare, “to call,” and means the work a person is called to by God.
There are all different kinds of voices calling you to all different kinds of work, and the problem is to find out which is the voice of God rather than of society, say, or the superego, or self-interest.
By and large a good rule for finding out is this: The kind of work God usually calls you to is the kind of work (a) that you need to do and (b) that the world needs to have done. If you really get a kick out of your work, you’ve presumably met requirement (a), but if your work is writing cigarette ads, the chances are you’ve missed requirement (b). On the other hand, if your work is being a doctor in a leper colony, you have probably met requirement (b), but if most of the time you’re bored and depressed by it, the chances are you have not only bypassed (a), but probably aren’t helping your patients much either.
Neither the hair shirt nor the soft berth will do. The place God calls you to is the place where your deep gladness and the world’s deep hunger meet.”
Beyond Words: Daily Readings in the ABC’s of Faith, “Vocation.”