Friendliness
إنّ أحسن ما يألف به الناس قلوب اودّائهم ونفوا به الضّغن عن قلوب أعدائهم حسن البشر عند لقائهم والتفقد في غيبتهم والبشاشة بهم عند حضورهم
One of Imam Ali’s (AS) sermons:
Friendliness to others – namely asking after them in their absence and smiling and showing cheerfulness in their presence – when meeting them is the best thing they can do to win the hearts of their dear ones and remove the spite from the hearts of their enemies.
(Tohfatul Oqul, p. 218)
Hadith Commentary:
Friendliness wins people's affection and makes the hearts grow fonder. ‘Friendliness is half of wisdom,’ as an Islamic tradition goes. All the officials of the Islamic system, especially the clerics who are in a position of responsibility in a department or a government organ, must consider this tradition as particularly noteworthy. This is because the clients are not at the same level in terms of their faith and, therefore, there is a strong possibility that unfriendliness towards them may put them off religion and shake their faith. Conversely, good manners attract them towards religion and make them optimistic about Islam. ‘The believer puts on a happy face while he is sad at heart.’
Source: khamenei.ir
Other links:
Giving Advice to Your Family
Real Followers of Ahl-ul-Bayt
Righteousness of Intentions
Quran, a source of advice
Control your temper
True worship
Nobility
Slander
Doubt