Action can also be an article of ones scientific conviction. There is a TV program called Brainiacs where some some mad cap science geeks put the laws of physics to the test in extreme ways that could kill them if the laws went wrong! Fortunately, nobody has yet died because obviously the laws are not wrong.
However, there is obvious a tradition behind this scientific conviction which these Brainiacs have studied enough to understand what they are doing. Likewise, nobody starts an activity to expand their consciousness if they do not have faith in such a thing being possible.
But all faith is bad from my point of view. I am not dedicating so many years of my life to Yoga out of faith, but out of scientific conviction.