Let not a group scoff at another group , it may be that the latter are better than the former ; nor let ( some ) women scoff at other women , it may be that the latter are better than the former , nor defame one another , nor insult one another by nicknames . How bad is it , to insult one 's brother after having Faith [ i.e. to call your Muslim brother ( a faithful believer ) as : " O sinner " , or " O wicked " , etc . ] .