Just know that you are surrounded by people who have found something that you know doesn't exist, but that they know personally. History is full of such examples and their stories.
Run that through the scientific method...if you can devise the right experiments to test for that.
With our limited senses, we are only able to discern and experience a very small sliver of the electromagnectic spectrum.
For most, that's all we knew/know for sure, scientifically, until we built devices to reveal more of the world we live in.
We have learned much compared to where we humans started from, but we know so very little about what actually is.
There certainly are. Millions know personally that such things as Bigfoot, ESP, dowsing, angels, demons, astrology, UFOs, ghosts, crystal healing, faith healing, and homeopathy work / are real. And they're all so much BS.
Let's not forget that over a billion people know personally that there is only one God (Allah), and Muhammed is his prophet.
Belief is meaningless. And for the record, I don't *know* that God doesn't exists. I'm an agnostic.
We have learned much compared to where we humans started from, but we know so very little about what actually is.
Compare the knowledge that advances in science have given us in, say, they last 200 years to the knowledge that advances in theology have given us in the last 2000 years.
I'll stick to science. It's the best tool ever invented to investigate the nature of the universe.