I really need to understand something.......?

Ok so lately I have been thinking a lot about you know like universe and stuff politics ect. I am just wondering why people can be so so so nice but other people can be such d---h bags I also don't understand why people need money it just seems to wreck the society you know because if we had know money no one would get paid but no one would need to pay as everything would be free??? Van you please help!?