Belief
A belief was the conviction or acceptance of something by an individual that it existed or was true, especially without proof. Beliefs affected the morals and values of an individual. Beliefs were mostly related to religion. A set of beliefs was known as a belief system.

In 2266, after informing the crew of the  that they would be destroyed, Balok, the commander of the Fesarius, said, "We make assumption you have a deity or deities or some such beliefs which comfort you." ()

In approximately 3074,  thought all his life, without doubt, that he had known the truth about the  as depicted in the holoprogram The Voyager Encounter. The Doctor's EMH backup module never meant to throw his beliefs into doubt, but The Doctor could not deny what he knew to be true. ()

See also 
 Open-mindedness

External link 
 
Philosophy
Psychology
Religions