Money is a game we play to organize how we, as a society, spend our resources. It works because:

1. Usually, at smaller numbers, you get money by doing something for society: i.e., you have a job.

2. At larger numbers, money is economic decision-making power: people with the money decide what products get built, what movies get made, and so on. And usually, if you make a good decision with that money, you end up with more money and thus more power to make economic decisions; and if you make a bad decisions, you end up with less money and less power to make economic decisions.

Obviously these aren't always true. I'm not an anti-capitalist or a lassaize-faire libertarian: I want rules to cause our system to approximate the above two patterns as closely as possible.