Guess Guess Guess

Try to guess what am I:

I am a very important material to everyone...
I can caused happiness and joy...
I can even caused disaster and sorrow..
I can make people smile and laugh..
I can even make people cry and suffer..
I can make people' s dream comes true..
I can even make people fight with each other..

People work hard to get me..
People will even quarrel with their besties to get me..
People will even kill each other to get me..
People can never see anything else besides me..

I AM EVERYTHING!!
So, try to guess what am I??