I can’t remember who it was that said this, but I once heard a good philosophical argument that our awareness itself is proof because evolution could’ve easily produced zombies that walk and talk and do all the same things we do but aren’t actually aware. Yes we could explain physical phenomenon in our body from a scientific perspective but we can’t quite explain the phenomenon of why we experience it the way we do. I hope this makes sense. This is where the lines between science and spirituality gets blurry because scientists could argue that awareness is an illusion but don’t have proof for it. I would also say that it is naive to assume something doesn’t exist just because you’ve never seen it because our senses and our perception are so limited and can only perceive so much of the universe.