The human body has no objective sense organ. It cannot differentiate from what the brain thinks is happening and what is actually happening, and thus, what you think is happening can have the same effect on your body as it actually happening, at least to an extent.
This is how the placebo effect works, but it's also why if you honest-to-goodness believed that you were Bugs Bunny, a lie detector would not contradict you. It's also why being convinced that everybody hates you can make you depressed even if they don't.
So, if you deadass believe that saying words into the air can heal you, you might expect it so much that you start to feel what you think is healing. That's why faith is so vital to religion.
