In spite of one's own best intentions and personal integrity, however, there still remains the possibility that a friend might become an enemy.
There is a friend who changes into an enemy, and will reveal a quarrel to your disgrace. Sirach 6:9
A neighbor might, by an unintentional slip of the tongue, bring forth the possibility of enmity (19:16). More malicious neighbors and friends might cause injury,240 feign friendship only for their own selfish advantage,241 or they may have been an enemy all the time and only appeared to be friends.242
Sirach also reveals that the shift from friendship to enmity might be due to the social context.243 The rich have friends who steady them through the minor mishaps of life. The humble, on the other hand, are roughly treated even when they fall and deserve genuine sympathy and aid (13:21-23). Related to the wealthy are the observations that friends
243 Certainly Sirach does not intend that the social environment necessarily overwhelms people; he is perceptive enough to observe, however, that some social settings might well predispose people to behave a certain way, but this observation does not constitute a kind of social determinism.