Allah, the Wise, has said:
وَ اِنْ طاَئِفَتاَنِ مَنَ الْمُؤْمِنِيْنَ إقْتَتَلُوْا فَأَصْلِحُوْا بَيْنَهُما
"And if two parties of the believers fall into a quarrel, restore peace between them two" 
Imam Sadiq (a.s.) said:
لَأَنْ اَصْلَحَ بَيْنَ اِثْنَيْنِ اَحَبُّ اِلَيَّ مِنْ أَنْ اَتَصَدَّقَ بِدِيْناِرَيْنِ
"Reconciling between two (disputing) persons is dearer to me than giving two dinars in charity." 
One of the mandatory acts required of us is the inspection and rectification of our souls. Until a person reforms himself, he would be unable to bring about reformation within others. Attempting or achieving reconciliation between the brethren-in-faith, relatives, or neighbours, is an attribute which is immensely loved by God.
For the purpose of establishing unity and harmony instead of disunity and discord, it is essential to make every possible effort to bring about reconciliation. In fact, in certain circumstances, it becomes permissible to resort to white lies. At times, it may even become obligatory, so that dissension dies down and discord subsides.
1 - The Order to Reconcile
Once, during the time of Imam Sadiq (a.s.), Abu Hanifah, the administrator of Hajjaaj, had a quarrel with his son-in-law over some inheritance. Mufadhdhal Ibn U'mar Kufi (one of the close companions of Imam Sadiq (a.s.)) happened to pass by at the time. When he overheard the dispute, he stopped and said to both the men:
"Come with me to my house."
They did as requested. Upon reaching the house, he entered inside only to come out shortly afterwards with a bag containing four hundred dirhams, which he gave to both men and made peace between them. He then explained:
"This is not my money but Imam Sadiq's (a.s.). He hadinstructed me: Whenever you happen to see two of our Shiites disputing over money, give them this and make peace between them."
2 – Exercise Caution in Reconciliation
A'bd al-Malik says:
There arose a dispute between Imam Baqir (a.s.) and some of the children of Imam Hasan (a.s.). I approached the Imam (a.s.) and sought to intervene in the matter in order to reconcile them, but the Imam (a.s.) advised:
"Do not say a word in this dispute for our problem is like that of the old man from Bani Israel, who had two daughters. One of them was married to a farmer, while the other to a pottery-maker. Once he decided to pay them a visit. He first visited the daughter who was the wife of the farmer and reaching her house, he inquired about her health. The daughter said: "Dear father, my husband has cultivated a large area of land and if it were to rain, we would be the most prosperous of the entire Bani Israel."
Then, proceeding towards the house of the other daughter, whose husband was a potter, he inquired about her health.
The daughter said, "Dear father, my husband has moulded pots in great quantity and if God were to withhold the rains till his pots dry up, we would be better off than the entire Bani Israel."
As he departed from the house of his second daughter, he prayed:
"O' God! Act as You deem fit for, in this situation, I cannot pray for either of them."
The Imam then said to me, "You too cannot intervene in this matter. Be wary, lest you show disrespect to either of us. Your responsibility towards us, because of our relationship with the Holy Prophet, is to treat all of us with deference and esteem."
3 – Reward of Reconciliation
Fudhail Ibn A'yyadh says:
A distressed man once took some rope, which his wife had woven, to the market in order to sell it so as to save himself and his family from hunger. Having sold it for one dirham, he intended to purchase some bread when he came across two persons quarrelling and trading blows with one another over one dirham. The man stepped forward, gave them a dirham and established peace between them. Empty-handed once again, he went home and narrated the entire incident to his wife. She expressed happiness over his conduct. On searching the house, she found an old dress, which she handed to her husband, so that he could sell it and procure some food.
The man brought the dress to the market but there was nobody willing to buy it from him. Looking around, he saw a person with a putrefied fish in his hand.
He approached the man and said, "Let us exchange our goods. You give me your fish and I shall hand you my dress."
The fish-seller agreed and the man returned home with the fish.
His wife busied herself with cleaning the fish when, suddenly, something valuable popped out of its stomach. She handed the object to her husband to sell in the market. The man sold it for a very good sum and returned home, but he had hardly entered the house when a destitute person came up to the door and called out, "Provide me from that which God has granted to you."
As soon as the man heard the cry, he brought out all the money and invited the poor man to take as much as he wanted. The beggar picked up some money and started to walk away. But he had just gone a few paces, when he returned and said:
"I am not a poor person. I have been sent by God and have to inform you that the amount of money which has reached you, is your reward for reconciling those two quarrelling persons."
4 – Mirza Jawad Agha Maliki
Regarding the mystic, Mirza Jawad Agha Maliki (died 1343 A.H.), it has been recorded that during the initial stages of his journey in quest of spiritual purification and after having studied under his teacher, the great mystic Mulla Husainquli Hamadani (died 1311 A.H.) for two years, he complained to the teacher:
"In my quest for spiritual purification, I have not been able to achieve anything as yet!"
"What is your name?" asked the teacher.
He replied, "Don't you recognize me? I am Jawad Maliki Tabrizi."
Husainquli Hamadani enquired, "Are you related to such and such Maliki family?"
Mirza Jawad replied in the affirmative, and then went on to speak critically of them.
"Whenever the time comes for you to place their shoes before them to wear (which you regard as base and lowly), I shall personally come to guide you," advised Husainquli Hamadani.
The next day when Mirza Jawad went for his classes, he seated himself behind all the other students and from that day on, slowly and steadily, he began to become acquainted and friendly with the students of the Maliki family living in Najaf. This continued until a stage was reached when he would even place their shoes before them to wear. When the relatives living in Tabriz came to know of this, the dissension and discord that existed among the members of the family, subsided and peace was established amongst them.
Later Mirza Jawad approached his teacher, who said to him:
"There are no new instructions for you (after that of reconciling the members of the Malikifamily). Continue to act upon this order of the Sharia'h and derive benefits from it."
Author's note: Incidentally, the book Miftaah al-Falaah of the late Sheikh Bahaai is an excellent book to actupon." 
Slowly, Mirza progressed in his quest. He came to the Hawza of Qum where he embarked upon training and guiding students in the field of spiritual purification. A great number of people, the common public as well as the educated elite, benefited from him and his teachings.
5 – Advice of Mamun's Minister
Once, Mamun the Abbasid Caliph, became furious with A'li Ibn Jahm Saami, the court poet, and in a fit of anger ordered his servants:
"Put him to death and confiscate all his possessions."
Mamun's minister, Ahmad Ibn Abi Duwaad, in a reconciliatory move, approached him and asked, "If you kill him, from whom shall we confiscate his wealth."
"From his heirs," replied Mamun.
Ahmad said, "In such an event, the Caliph would not have confiscated his wealth but that of his heirs, for after his death he shall cease to be the owner of his possessions. And seizing the wealth of one for punishing another is an act of injustice, which does not befit the rank ofCaliphate!"
Mamun said, "Well, if this is the case, imprison him, confiscate his wealth and then put him to death."
Ahmad departed, imprisoned A'li Ibn Jahm and held him alive till Mamun's anger had subsided. Mamun pardoned A'li Ibn Jahm and commended the minister for his conduct and elevated him in rank and status.
 Holy Qur'an, ch. Al-Hujaraat, (49), vs. 9.
 Al-Kafi, vol. 2, pg. 167.
 Muntahal Aa'maal, vol. 2, pg. 249.
 Daastaan-ha Wa Pand-ha, vol. 1, pg. 134; Raudhah al-Kafi, pg. 85.
 Namunah-e-Ma'arif, vol. 1, pg. 218; Farajun Ba'd al-Shiddah.
 Taareekh-e-Hukamaa Wa U'rafaa, pg. 133
 Lataaif al-Tawaaif, pg. 98.