On Yom Kippur in the prayer of על חטא we enumerate many transgressions, and beseech forgiveness from Hashem. It has often been asked why we confess many offenses that we obviously did not commit. How can we, on this most holy day, stand and recite lies about ourselves?
One answer given is: שכל ישראל ערבים זה בזה, all of Israel are responsible one for another. (Shev. 39a) Although we ourselves have not committed some of these sins, we are nevertheless responsible for our fellow Jews who may have committed them.
Support for this opinion may be found in the Portion we read this week. The Torah says: אִישׁ אוֹ אִשָּׁה כִּי יַעֲשׂוּ מִכָּל חַטֹּאת הָאָדָם, “…a man or a women who commits any of man’s sins…”. This verse speaks of an individual, one person who transgressed. The very next verse says: וְהִתְוַדּוּ אֶת חַטָּאתָם אֲשֶׁר עָשׂוּ, “They shall confess the sin that they committed…”’. (Num. 5,6-7) This verse refers to the sinners, in plural.
From this we can see that even if an individual performs an offence, everyone has to confess the transgression. We are accountable for each other and must help each other do what is right. If we don’t succeed, then all share in the guilt, and must also confess this wrong doing.