If we could create a world where everything is in order and there is only happiness. Who would not want to live in that world.
Now just for a moment go back in time a little bit when we had this planet and no humans. Everything must have been in order. The order was so perfect and complete and that formed the basis of the new species the homo sapiens who were more evolved.
The homo sapiens had cognitive ability to imagine and understand reality of coexistence of all the things. They started with one thing at a time and understood the rules of matter, plants, animals etc.
They created some artificial things like country religion money ethinicity and sadness. In reality there is no saddness.
There is only coexistence and musical happy order between things. Now that knowledge has been found and slowly permeating in the society.
There has to be no reason or logic or agitated state to be happy just being is happiness. Human beings by making an effort can imagine problems while in reality it is only what is there. This improper and incorrect use of the faculty of imagination creates Sadness and the default setting of happiness will eventually prevail. This is the result of studies on people who lost parts of the body in accidents.
Happiness is the default mode and by understanding coexistence you can easily maintain that status quo and no need to be Sad at all.