We tend to think of "despising" something or someone as just a strong way of expressing dislike, but there is a further shade of meaning there. As the Free Online Dictionary puts it, it also means "to regard (something or someone) as unworthy of interest or concern." This meaning comes into play as "despise" is used in the Bible; it indicates that a person in a particular spiritual state cannot understand or value things belonging to a higher spiritual state, and thus regards them as nothing.