How do we show others their errors?

It is often difficult to show people their errors, to tell them what theyre doing is wrong, bad, etc etc.. There are people who do not liek ot accept their common mistakes, or when they hear of them they dismiss them, let them pass over their heads, some may even react in an angry defensive way..

Once upon a time, the grandchildren of the prophet of Islam, Hassan and Hussain were doing their abolutions (a ritual that is performed before prayers, involving washing the feet, hands, arms, face and scalp), when they came across an elderly man who was not performing his ablutions correctly, in order for them not to hurt his feeling, they decided to tell him to see who performed their abolutions more correctly, Hassan or Hussain? Each then performed his wudu (abolutions in arabic) in the best way possible. The man then realised his mistake and thanked the two youth for correcting him.

From this example we can see that there are ways to show people their errors without really hurting them or offending them.

Somtimes life requires you to be patient with others, to be tolerant with their ways, and little for little they end up learning their mistakes.. never give up on people, never stop loving them, always be there to serve them, teach them, love them, and protect them.. for why else are we representatives of god?