Belief and behaviour.
All beliefs influence our decision making and behaviour.
(1) Belief is inherently tied to our psychology. (2) Our psychology is inherently tied to our decision making and behaviour. (3) Therefore we have a link between what we believe to be the case, to our psychology, to our decision making and behaviour.
By definition, if our decision making is tied to our psychology, and our beliefs are tied to our psychology, then it is necessarily the case that our beliefs are tied to our decision making: belief > psychology > decision making, etc.
Our psychology defines who we are, thus anything which affects our psychology will necessarily have some influence on us.
"It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring" -- Carl Sagan