First, I should mention that I ask myself all the following questions as well and that I do not claim to have found any answers. This is to be understood as a conglomeration of thoughts I have come accross and have come up with myself in order to explore possible answers. As always it is exploring, not dogmatizing.
Work is something you do regularly because you have to. It is something so abominable and boring that you need to get paid for doing it. Further, you have to work because you need money.