“If somebody reproaches you and makes you feel ashamed of any of your defects, do not make him feel ashamed of any of his defects.”
[Abu Daud]
Usually, when somebody points out one of our shortcomings, we immediately become defensive and start finding faults with them. But the advice of our beloved Rasul Allah (sal Allahu alaihi wa sallam), is that we should listen quietly and evaluate what we are being told. If there is something we can improve about ourselves, it is only to our own advantage to do so. If the criticism is unjustified, then we are rewarded for our patience and good behaviour in not retaliating. The angels will take care of defending our honour. Starting a counter attack opens the door for Shaytaan to come in and take over.