Do not strut arrogantly about the land. You will certainly never split Earth apart, nor will you ever rival the mountains in height. All of that is evil action and hateful in the Sight of your Lord.
(Surat al-Isra', 37-38)
The Messenger of Allah (saas) said: "Shake hands, and rancor will disappear. Give presents to each other and love each other, and enmity will disappear." (Sahih Muslim)
The Prophet (saas)said: "Give present to one another, and you will then have love for one another." (Imam al-Ghazzali, Ihya' `Ulum ad-Din)
Good conduct is the root of love for one another, and bad conduct is the root of hatred, envy, and enmity. (Imam al-Ghazzali, Ihya' `Ulum ad-Din)
The Prophet (saas)said: "If two brothers meet with each other, they are like two hands, one of which wipes the dust off the other." (Imam al-Ghazzali, Ihya' 'Ulum ad-Din)
Do not envy one another, do not hate one another, do not turn your back on one another (in discontent), and be the servants of Allah like brothers. (Sahih Bukhari and Sahih Muslim)
Love Allah, because He nourishes and sustains you. Love me, because Allah loves me. (At-Tirmidhi)
The Prophet (saas)said: "Allah raises him up who humbles himself for Allah. He humbles the one who is insolent. Allah loves one who remembers Him much." (Imam al-Ghazzali, Ihya' 'Ulum ad-Din)