What is a belief-system?
"The mind is everything. What we think we become." [Buddha]
Paraphrasing the above within the context of belief-systems,
"Your belief-system is everything. What you think and believe, you become."
Your belief-system determines your courage, fears and behaviours.
As various sages, and authors have written:
I was chatting to a photographer today who's quite 'spiritually aware'. He's up to speed, so to speak, with the intuitive, artistic dimensions to life. In fact he spoke in terms of waves, and how we can build them (but not strictly from a quantum mechanical perspective -- but I digress).