According to Dictionary.com, "belief" is an opinion or conviction of something. Beliefs develop from facts that are considered truthful, even without positive knowledge or proof. For instance, the presence of a supernatural being, or God, is a belief that is widely held among many people even though there is no documented proof that such a being exists.
Beliefs are mental attitudes established after an individual agrees with the proposition's truth. Such truths can be based on morals or on a body of facts presented by experts. In any case, the beliefs a person holds determine how that individual relates to those with shared or divergent beliefs. Religion is a belief system in which people believe that there is a divine force responsible for the creation of life in the universe. A divergent belief to religion is the theory of evolution, which states that life in the universe formed as a result of cataclysmic events and chemical reactions.
Both of these beliefs are validated by specific facts and supporting evidence; therefore, it is difficult to determine which one of these beliefs is the ultimate truth. However, in order for a belief to be considered as truth, it does not need to be accepted by everyone -- only by those who accept the facts supporting the idea of the belief.