What was the root issue as to why humanity failed to master their domain through struggles with relationships and sickness?

The problem goes back almost to the beginning of history where leaders started to focus on power and territory instead of improve socialism in order to unify the world as one and unique nation. Since the beginning of wars governments have wanted to accumulate material things, not to share them with their people, but to keep it on their own elite.

This have caused the separation of what we call "nations" and the segregation of the ones we call "weak" due their social status.

Then came the Modern Era and all the scientific revolution began, this seemed to be a great solution for sickness with all the new medicines appeared to be cure, but the abuse of them and the capitalism made it lucrative. At this postmodern era it is necessary to combine humanism to reunite all the world from the individuals to the nations; and stop consuming medicines to cure the effects of medicines.