What Are We Working Toward?

I relised that we work and work knowing that soon we we become old and soon we will die. Once we are dead the only thing carrying our "soul" is humanity. Humanity is the body and us individuals are the cells. What is our "body" working towards? Why shouldn't humanity work together to better everyone's existence, rather than working solely for ones own personal gain. Why do we as humans find such joy in the suffering of others. It reminds me of big daddy and how Adam Sandler would hurt himself solely for the amusement of the boy he was watching.