That is religion, mythology and lot of superstition. I agree. I can't stand much of all that myself.
If you want to understand spirituality without the religious stuff...go for Yoga or Vedanta. Spirituality is essentially about what each of us is independent of the body and mind.
Something I can speak about with experience that you could if you wanted to scale up to most things in life, I wear hearing aids one behind each ear, I take the off at night for obvious reasons and then put them back on/in each morning the sound they transmit into my ears is a rather tinny sound and it would be reasonably easy for any competent sound engineer to prove that the tinny sound the small speakers transmit to my ears will remain the same tinny sound for all of the time I'm wearing them.
But no, guess what, my brain, independently of anything I can control, turns the sound into an approximation of whatever it thinks the sounds it's dealing with should sound like and to me these sounds are no longer tinny sounds, to me, they all sound as warm and natural as my brain thinks they should be.
One of the jobs our brains do without any prompting is to make every effort to make sense of its surroundings, lots of things in our short lives don't necessarily make sense and I'm sure a part of these, senseless to me, religious or ideas spiritual, dependent on your take on the meaning of spiritual, are partly made up by our brains again trying to make sense of this world we all live in, nothing mystical about it, although I must concede it looks that way.
There's so much more to that simple statement of Russell's about the tea pot, than is immediately obvious.
Regards ippy