I found this article to be helpful:
http://www.nytimes.com/2015/09/06/opinion/arthur-brooks-rising-to-your-level-of-misery-at-work.html
"I believe that service reduces stress and raises satisfaction because it displaces the object of attention from oneself. When I am working for myself, any disappointing outcome is a stressful, unpleasant reflection on me. When I am serving, on the other hand, the work is always intrinsically valuable because of its intention. Adopting a service mind-set guarantees some measure of success.
Through this added layer of intentionality, almost any work can be understood as a genuine service job. The type of work is actually less important than the attitude of the worker. This point is illustrated in the parable of a traveler who happened upon stonemasons. When he asked the workers what they were doing, one mason simply replied, “I am making a living.” But another stonemason answered differently: “I am building a cathedral.”"