An object that represents an idea

A symbol is the use of a single entity to represent an abstract concept. It occurs when an object, person or circumstance reflects an abstract concept in addition to a literal meaning. Symbols can appear in literature in a variety of ways: an entity, a word, a figure of speech, an action, an occurrence, or a character. In simpler form if that make sense, a Symbol is an object that represents and idea.

Explanation:

we would need to be able to read the passage in question to determine which factor allowed david believe he could defeat goliath. post the passage, and i'd love to out.