Money is not good, it is not evil, it is simple.
Money is a simple, easy way to trade. Today we don't trade cows, chickens or fur; we trade money.
Money is used to represent things like previously mentioned. It had to. For instance, if you had 3 cows to trade you could not tell someone you had 5.
Look at the picture above. Think of money as a receipt and that pie as a herd of cattle. Lets assume there are 8 cows. Judging by the size of the slice, that piece would be worth one of eight cows. However your money, or receipt, does not say '1 cow' it simply says '1' (or 1 dollar as we are more familiar with). And to start with there are 8 receipts, one for each cow. Your money represents 1 out of 8 receipts, not one cow (Don't ever forget that!)
Now you go around trading your '1s', and as most everybody is aware, they are worth one cow. But the bank gets greedy. They start printing more receipts (money) out of thin air! There aren't anymore cows being made, just receipts. Lets say they printed 8 more (doubled the money supply), now we have 16 receipts or '1s' for the same 8 cows.
Remember your receipt is one, not one cow, just a made up one. But now there are 16 receipts so your one is now 1 of 16 not 1 of 8. What is 1/16 of 8 cows? Well it sure as hell isn't one cow. Your money is now worth only half a cow, just like that, and as simple as this example.
Today we trade and put value on more than cattle. Our GDP as we call it, or Gross Domestic Product, is the sum or total of all that we produce. Everything from cars to TVs to homes, oil, planes, etc (all the cows). Your money is a receipt of this, a representation. But when we expand the money supply (print more money) without making more stuff, just like in the example above, your money becomes worth less. So after reading this I hope you never ask yourself why things seem to cost more and more. Now you know.
Obviously this is a very basic example, and there is more to it, but even the stuff not talked about in this post is still simple. Money is made to be complicated so we give up on trying to understand it and just go with the flow. Ever tried listening to someone that made no sense? Did you ask them to stop and try redefining their subject in a way you would better understand? Nope! You did what we all do, smile and nod. That is what we do with money, just maybe with a little less smiling but still a whole lot of nodding.
If someone ever tries to tell you money is more complicated than this, walk away, they either don't have a clue, or are trying to take your money.