Hope is an emotional belief in the possibility of positive outcomes related to events and circumstances within one's personal life, which may regard a minor issue or an extremely important matter. Hope implies a certain amount of perseverance - believing that something is posssible even when there is some evidence to the contrary.
Hope was personified in Greek mythology as Elpis. When Pandora opened Pandora's box, she let out all the evils except one: Hope. Apparently the Greeks considered Hope to be as dangerous as all the world's evils. But without hope to accompany all their troubles, humanity was filled with despair. It was a great relief when Pandora revisited her box and let out hope as well.