A small false thought does not stay small. Like something worked quietly through dough, the ego's hidden pretense spreads through the whole of a mind until every perception is faintly soured by it. The split between what a mind shows and what it secretly believes is itself the belief in separation, dressed as virtue and set to work in the dark.
To be watchful is not to fear this thing but to refuse it entry before it has room to grow. A mind that lets love examine its hidden corners early, while the falseness is still a trace, keeps the whole from being turned. What is caught small is corrected easily.
Leaven: the small hidden thought that will not stay small, spreading its quiet corruption through the whole of a mind until every perception is changed
Pharisees: the part of the mind that shows one face and believes another, the pretense in which separation disguises itself as goodness