Belief is: faith, credence, credit, assurance, doctrine, conviction, acquiescence, dogma, conclusion, judgement, persuasion, principle, idea, inevitable.
Belief is trust. You can trust a person, an idea, a statement, a decision or a path in life. It seems that this should require proof of some kind, evidence, but often we believe without evidence and sometimes we believe in things or people even when the facts seem to point against the belief. One of the most popular narrative forms is about the trusting, believing person who holds true to a person or idea when everyone else says no, and the unfolding of how that is proven true.
It was the earlier word for what we now call faith. Faith overall meant loyalty to a person or loyalty to a promise or oath. Belief meant you accepted something as true, as real.
Belief is an essential requirement for creation, for growth. It is a prerequisite for friendship and love; it is an underpinning of teamwork. This mental acceptance of another person or group, what he/she/it stands for and what potential the relationship holds can carry us through a great deal of difficulty. But the potential alone is not enough; we must expect that something is and will be.
“To believe only possibility is not faith, but merely philosophy.” Sir Thomas Browne