How Do We Find Our Calling?

Vincent van Gogh bounced-around, from job to job, as he tried to find his calling (or purpose) in life. Nothing seemed to work until he realized that he was meant to be an artist.

What does it mean to have "a calling" in life? Is there a difference between "a calling" and "a job?" What is the difference? Could "a calling" and "a job" be the same? Why, or why not?

Vincent seemed to find his purpose, or calling in life, when he discovered his passion for creating art. His ability to draw and paint allowed him to create stellar art over the years, but van Gogh was unable to sell his art work. If, like Vincent, we are drawn to a particular field of work—but those endeavors don't result in payment for a long period of time—have we misunderstood our calling?

What if, like Vincent, our calling to a particular field is genuine, but it takes years of effort to generate income? Is it better to stick with what we love to do—and are really good at doing it—or to find a different job that at least helps us to earn a living?