Surah: Al-Hujuraat : verse :11
O you who have believed, let not a people ridicule [another] people; perhaps they may be better than them; nor let women ridicule [other] women; perhaps they may be better than them. And do not insult one another and do not call each other by [offensive] nicknames. Wretched is the name of disobedience after [one’s] faith. And whoever does not repent – then it is those who are the wrongdoers.
This is one more prove of how islam is a religion of peace.