why do we need money..?

To lead a comfortable life.

It's a standard currency used in exchange for things everyone needs. You can acquire what you want or need and there is a set value for the money that allows everyone to trade equally.

because society demands it

no longer can someone choose to opt-out of society by going to live in the mountains, now you're forced to live in a communal environment whether you want to or not, until you're sufficiently rich enough ot leave the community. even then, the government will come by ever year to collect "rent" (tax) so that you cna live. that is why you need money. because other people say you do, and if you don't, you'll wind up in jail or dead.

Its a sort of token that represents your power to buy things, services, products and everything that could be sold or bought.

Its needed by us because without it one would not be able to buy anything and lead life.

To (1) fulfil our desires and (2) earn more money.

To exchange for the things we need to survive? Food, water, shelter, etc?

It depends on person to person way of thinking... that what he/she want to do with money...

why do you have to buy food?clothes?