Any human activity counts as a firm belief in the necessity of that activity. Even if that activity has no meaning, since it is done, it expresses its agent confidence in its reality. His bodily involvement is a sufficient proof for its reality.
When we stop from doing them, we are overloaded with a huge amount of trivial beliefs. For avoiding the hard task of verifying their real meaning, we often ignore them altogether and rush in forming our beliefs according to our thought, as if the body would not contain any belief. With the result that all those spiritual beliefs can be contradicted anytime by those base bodily beliefs which were disregarded, but they did not disappear.
Less dangerous seems to refrain yourself from hastily claim spiritual beliefs. As long as someone lies in the nearby oh his unexpressed bodily beliefs, he might attempt to eliminate some of them which are meaningless. In this way, when he states a spiritual belief, there would be fewer reasons for being contradicted by his bodily beliefs.