This is different from any "remote possibilities" for multiple reasons. The first is that it is very widely believed, in one form or another. If it is wrong, then it is the biggest factual oversight the world has ever seen, by a long shot. That's hard to prove.
I don't know. There have been many factual oversights that have been shattered, with
great significance. "Earth not being the center of the Universe, stars not being dots of light" is going to be of huge significance when we expand to the stars. The Earth could maybe sustainably hold 10^10 people, our the Asteroid Belt
alone could hold 7,500 trillion people. We're talking about a 100-fold increase in the number of humans who can be alive in a couple centuries. We're talking about a geometric growth of our population rate for millenia longer than anybody a few hundred years could have thought.
Another factual oversight is that we used to think that the human brain was significantly unique from those of animals. Time and again, we're shown that this isn't true, and because brain research in animals can be translated into useful results into people means that we're able to understand our mind in MUCH greater detail than was ever thought possible. We can use mice to understand the fundamentals of humanity: morality, kindness, greed, love. We used to think that the mind was a separate entity from the brain, thankfully, we now know this is not true.
Secondly, its about what feels right, what helps you be a better person and live a better life
Fully agreed. People should do their utter best to find reasons to be good and loving. A 'good' world and a 'loving' world is so much better than the alternative, that it should be pursued at all opportunities.
, what helps you to prepare for what happens after death.
I have issue with this logic. Why would you trust a
feeling that tells you about the afterlife, when it's the same
feeling that had you believing that the Earth was covered in a Global Flood a few thousand years ago? This feeling was
verifiably false in an extremely-easy area to discern, why should it be trusted with telling us about the unknowable?