1.
acceptance of truth of something:
acceptance by the mind that something is true or real, often underpinned by an
emotional or spiritual sense of certainty • belief
in an afterlife
2.
trust:
confidence that somebody or something is good or will be effective • belief
in democracy
3.
something that somebody believes in:
a statement, principle, or doctrine that a person or group accepts as true
4.
opinion:
an opinion, especially a firm and considered one
5.
RELIGION religious
faith: religious faith