Differing Beliefs? Guess I Have to Kill You!

We all have our favorite explanation of how things work in life, our own ways of being able to cope with day to day misadventures and failings. Does it matter? Or is there some truth to the idea that we all create our own reality, and that if I believe something to be true AND act as if it is then it is to a large extent true for me, even if only in my own imagination?

Is Wall Street real, or is it an elaborate fiction created by a large enough group of people agreeing to play along? What about street gangs and other alternate economies? Are they real, or are they just fictions that seem real because a large enough number of people have agreed this is the way life will work in their neighborhood? Finally, what about religions? Does the system of reward and punishment so many of them believe is real actually exist, or does it only seem to do so because a large enough group of people have agreed it does?

If all of these things - and more - exist as real only because a large enough group of people agree that they do, that would mean we can change nearly anything (except things like the law of gravity) merely by deciding to do so and getting enough people on board. What might that mean for the future of our world? What might it mean for allegedly "unsolvable" social problems? It would mean we can solve almost any problem simply by deciding to do so!

The only things stopping us are fear and greed.