If it is for purposes related to spiritual practice, working can be viewed as a kind of supramundane practice. If the money is intended for ill purpose, even before any real action has taken place, evil karma will start being accumulated every day one goes to work. When working is simply a means for living, it results in neither good nor evil karma. So, action may be the same, but karma may not. And the determining factor is nothing but one’s motivation.

- Quote from The Right View, "The Three Differences"