We're told that in this arena "seeing is believing" is backwards, that we must first believe and then we will see.
Sorry, but that makes no sense whatsoever. It's in complete opposition to the scientific method...which works.
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.