Question: Will there ever be a time when the world works together and rid humanity of Disease, Hunger and War? Is this even possible?
Answer: Yes it is possible. But it won’t happen through “Imagining” it as we sing with John Lennon, and it won’t happen by foolishly repeating the same political, economic, social and military mistakes, “solutions” again and again, as we do right now all over the world.
In order to achieve what you asked about first we need to know why we could not achieve such a perfect Human society so far. And we could not build such a society because we are all born with an inherently selfish, egoistic and hateful nature. We all make calculations only for our own sake, profit at the expense of others.
This is not a “sin”, this is not “evil”, we were born this way, this is how we are programmed by Nature. But we also have a very unique Human mind capable of critical self-assessment, capable of initiating special self-correction, upgrade by using the appropriate, purposeful and practical educational method.
Thus the first step towards building a better, fairer, healthier, prosperous and sustainable global Human society is the right education, upbringing. Only this way can we make fundamental changes in ourselves, only this way can we rise above our instinctive nature through positive motivation, without coercion.