Surely all believers are brothers. So make peace between brothers and fear Allah that mercy may be shown to you. 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. (Surah Al-Hujuraat) (49:10-11)
Anas (May Allah be pleased with him) reported: The Prophet (PBUH) said, “Make things easy and do not make them difficult, cheer the people up by conveying glad tidings to them and do not repulse (them).”
[Al-Bukhari and Muslim].
Jarir bin `Abdullah (May Allah be pleased with him) reported:
Messenger of Allah (PBUH) said, “He who is deprived of forbearance and gentleness is, in fact, deprived of all good.”