The seventh Mishna in the first chapter of Pirkei Avos instructs us a teaching of Nitai HaArbeily -- "Harchek mishachein ra, ve'al tischaber le'rasha ......." Our Tanna teaches us that we should distance ourselves from bad neighbors and not join with wicked people. The Ben Ish Chai asks why the Tanna needs to warn about associating with wicked people when he has already warned us to distance ourselves from bad neighbors?

There was a Chasid who approached the Rambam before Yom Kippur to ask him why he should lie about asking for forgiveness for the sins of idolatry, murder and adultery when he knows that he never committed those transgressions. The Rambam told him that if he ever was boastful or became angry it was as if he committed the transgression of idolatry and that if he ever embarrassed his fellow then it was as if he committed murder. Thus it would not be lying to ask Hashem's forgiveness for these transgressions. An act such as idolatry is ra while a similar yet lesser sin is considered a shachein ra. One should distance himself from both sins and sinners.

My chevrusah's point was simple and important. Since a person's is strongly influenced by his chevrah, his chevrah should consist of people more excellent than himself.