Hadrat Sayyiduna Abu Sa'eed al-Khudri (Radi Allahu Anhu) narrated that the Beloved Prophet (SallAllahu Alayhi wa Sallam) said,


من رأى منكم منكرا فليغيره بيده ، فإن لم يستطع فبلسانه ، فإن لم يستطع فبقلبه ، وذلك أضعف الإيمان
When you see any wrong amongst you, change it physically, if you cannot then rectify it verbally. If this is not possible then dislike it in your heart and this is the weakest state of Imaan.


[Sahih Muslim, Kitab al-Iman, Page 44, Hadith 49]