Machine summary:
"Regarding this issue, Imam Ali (A) has stated: If the ruled fulfil the rights of the ruler and the ruler fulfils their rights, then right attains the position of honour among them, the ways of religion become established, signs of justice become fixed and the Sunnah gains currency.
Imam Ali (A) introduced this factor which creates disunity and described such a society as follows: The people of this time would be wolves, its rulers beasts, the middleclass gluttons and the poor (almost) dead.
Imam Ali (A) introduced spitefulness as a cause of division and considered it as a sign of impure nature and bad conscience: You are brethren in the religion of Allah.
Imam Ali (A) is one of the distinguished characters and leaders of Islamic world who has left great legacy in both practical management and leadership of Islamic society and theoretical explanation of theological and moral issues related to unity.
When we study the works and the life of Imam Ali (A), we learn that he (A) considered unity as the gift of the holy Prophet’s (S) mission which put all enmities aside and caused the divine blessings to embrace mankind.
From Imam Ali's (A) point of view, the factors which can create unity among the Islamic community are preserving good traditions, satisfying reasonable demands of people and making appropriate use of people’s emotions.
Imam Ali (A) views rejection of faith, worldliness, lawbreaking, being under the rule of the arrogant and disputes and enmity as factors which can create disunity and Muslims must avoid them."