Allah, the Wise, has said:
فَاصْـبِرْ کَماَ صَبَرَ أُُولُوا الْعَزمِ مِنَ الرُّسُلِ
"Therefore bear up patiently as did the messengers endowed with faithfulness bear up with patience." 
Imam Ali (a.s) said:
حَلاَوَةُ الظَّفَرِ تَمْحُوا مَراَرَةَ الصَّـبْرِ.
"The sweetness of success erases the bitterness of patience." 
For some, the initial phase of patience is bitter while its final phase is sweet, while for others, its initial as well as its final phase is bitter, while for yet others, patience, in all phases, is sweet.
One who exhibits patience willingly, refrains from complaining before the others and does not fret and fume, is of the Patient Ones, while one, who is not forbearing in the face of misfortunes and does not beseech and supplicate to Allah, is regarded as being of the Impatient Ones.
It is in the face of misfortune and calamity that a truly patient person is differentiated from a false claimant. A patient person is submissive in the face of adversities while one who claims falsely is overcome with perturbation, anguish and sorrow.
1 – Survival of Religion Lies in Patience
One day the Noble Prophet (s.a.w), accompanied by the Commander of the Faithful(a.s), had been heading towards the mosque of Quba when they happened to come across a lush-green garden. Witnessing it Imam Ali (a.s) commented: "O Prophet of Allah! It is a nice garden." The Noble Prophet (s.a.w) responded: "Your garden in Paradise is nicer!"
They passed by the garden and continued on their way; in the course of their walk they passed by seven gardens and on each occasion the same conversation ensued between the two. Then, the Noble Prophet (s.a.w) took Ali (a.s) into his arms and began weeping intensely, causing the Imam (a.s) to weep too. When he (a.s) sought to know the reason for the Noble Prophet's (s.a.w) weeping, he (s.a.w) said: "I suddenly recollected the malice that has taken root in the breasts of the people towards you and which they shall make manifest after my death."
The Imam (a.s) inquired: "O Prophet of Allah! What should I do?" He (s.a.w) advised: "Patience and fortitude. If you fail to exhibit patience you shall fall into far greater difficulties."
He (a.s) said: "Do you fear the destruction of my faith and religion?" He (s.a.w) replied: "Your (faith and religion's) existence lies in patience."
2 – Ease After Patience
The only son of an indigent woman had gone on a journey which had transformed into a protracted one. Extremely worried, she approached Imam Sadiq (a.s) and complained: "My son has been away on a journey, which has turned into a very long one and I am terribly distressed."
The Imam (a.s) said: "O' Lady! Be patient and control yourself."
The lady left, but after having waited for a few more days and with no sign of her son's arrival she was not able to take it any more and so, approaching the Imam (a.s) again, she said: "My son has still not returned. What should I do?"
The Imam (a.s) said to her: "But did I not advise you to be patient and exhibit fortitude." She lamented: "By Allah! I have reached the limit of my patience and do not possess the strength to bear this separation any more!"
Hearing this, the Imam (a.s) said: "Return home for your son has arrived."
Confounded, she returned to her house only to find her son back from his journey. Even as she was overjoyed at seeing him, she thought to herself: "How did the Imam (a.s) know that he had returned? Does Revelation descend upon him? Let me go and ask him about this issue."
Approaching the Imam (a.s) she asked: "Just as you had informed, my son has returned from his journey. But tell me, do you receive revelation that you were able to inform me of the unseen?"
He (a.s) said: "I deduced this from one of the traditions of the Noble Prophet (s.a.w). He (s.a.w) had said:
عِندَ فَناَءِ الصَّبرِ ياِتيِ الْفَرَجُ
"When man's patience reaches its end, ease and relief sets in upon him." When I observed that your patience had reached its termination, I realized that relief had arrived and so informed you that your son had arrived and my deduction proved to be correct.'"
3 – The Patience and Fortitude of Bilal
Bilal was originally from Abyssinia and in Madinah, was one of the slaves of the tribe of Bani Jama.' After he had embraced Islam he had to suffer intense hardships at the hands of his owners.
During the onset of Islam those in Mecca who had embraced the faith had to face great adversities - especially those, who did not possess any familial or tribal support, or were slaves and servants. Some, due to the intensity of sufferings, even backtracked from their (new) religion but Bilal exhibiting great patience, increased in steadfastness as thus, his owners increased their torture upon him.
Abu Jahl would force him to lie on his stomach on the hot sands of Hijaz, pin him down by means of a millstone till his brains would almost come to a boil due to the intensity of the heat and then say to him: "Deny the Allah of Muhammad!" However, all that Bilal would say was: "Ahad Ahad" - meaning Allah is One.
One of those, who greatly persecuted him, was Umayyah Ibn Khalaf, who used to torture him repeatedly. However, as Divine decree would have it, he was killed in the battle of Badr at the hands of Bilal.
During one of those occasions when Bilal was being tortured, the Noble Prophet (s.a.w) happened to pass by. Witnessing him, he (s.a.w) said to Abu Bakr: "Had I possessed money, I would have purchased Bilal." Later he (s.a.w) approached his uncle Abbas and said: "Purchase Bilal for me." Even as Abbas went in search of the woman who owned him, Bilal was being subjected to torture and persecution - pinioned under the weight of heavy stones and almost on the verge of death.
Abbas approached the woman and expressed his desire to purchase Bilal whereupon she began to criticize and speak ill of him, but eventually sold him. Thus, Bilal, as a result of his patience in the face of torture and persecution, became free and entering into the services of the Noble Prophet (s.a.w) he became his muezzin.
4 – Patience is Better than Retaliation
When the battle of Uhud had concluded, the Noble Prophet (peace be upon him and his family) dispatched Harith Ibn Samt to search for the body of his uncle, Hamzah, amongst the dead. When Harith witnessed that Hamzah's liver had been taken out and his body mutilated by cutting off the ears, nose and other parts of the body, he could not bring himself to inform the Noble Prophet (s.a.w) of this unpleasant occurrence.
As a result, the Noble Prophet (s.a.w) himself arrived amongst the dead, but when his eyes fell upon the mutilated body of his uncle, he was immensely disturbed. As he wept, he said: "By Allah! Nothing has disturbed me more than this. If Allah grants me dominance over the Quraish, I shall mutilate seventy of their individuals."
At that moment, Jibrail descended with the following verse: "And if you take your turn, then retaliate with the like of that with which you were afflicted; but if you are patient, it will certainly be best for those who are patient," whereupon the Noble Prophet (s.a.w) said: "I shall exhibit patience over this calamity."
The person who killed Hamzah was Wahshi - the slave of Jubair - who, upon the orders of Hind (Muawiyah's mother. Her father, 'Atabah, had been killed in the battle of Badr) had torn open Hamzah's stomach, pulled out his liver and presented it to her. Taking the liver she bit into it, but by Divine decree was unable eat it. Arriving at Hamzah's body, she went on to mutilate it and then rewarded Wahshi by gifting him her necklace, bracelet and ear-rings.
5 – The Wedding Night
Sibt al-Sheikh has narrated: "One of the elders of Arabia - the chief of a tribe that dwelled in the environs of Baghdad, decided to marry his son to a maiden from amongst his relatives. As per the custom prevalent there, the marriage and its consummation was supposed to take place on the same night. On the appointed night preparations were made for feast and entertainment, and the supreme religious authority of the Arab world - Sheikh Mahdi Khalisi, was invited to recite the marriage formula.
Some of the youths proceeded towards the bridegroom in order bring him to the marriage gathering in a special ceremony and with special formalities. As was their custom, they began firing bullets into the air and in the process a bullet from the gun of one of the youths - a Sayyid (descendant of the Noble Prophet (s.a.w)) - accidentally struck the bridegroom in the chest and killed him.
Witnessing this, the Sayyid youth ran away and the episode was brought to the attention of the bridegroom's father. The late Sheikh Mahdi Khalisi, coming to know of the incident, instructed the father to exhibit patience and advised: "Do you know that the Noble Prophet (s.a.w) has a great obligation upon us and all of us are in need of his intercession; this youth did not do this intentionally but it was by providence that the bullet happened to strike your son killing him. Forgive this youth for the sake of his grandfather (s.a.w) and exhibit patience over this misfortune so that Allah grants you the rewards of the Patient Ones!"
Upon hearing the Sheikh's counsel the father of the bridegroom became silent and after little reflection said: "We have numerous guests now and the occasion of joy has been transformed into an occasion of grief. For completing the right of the Noble Prophet (s.a.w), call the Sayyid youth and instead of my son, marry him to the maiden and lead them to the bridal chamber!"
The Sheikh praised and commended him (for this gesture of his). When the people went after the Sayyid youth and informed him that he was to get married in place of the chief's son he initially refused to believe it, thinking it to be a ploy to seize him and kill him.
However, ultimately the Sheikh married the maiden to the Sayyid youth on that night itself, while the dead son was buried the next day."
 Suratul Ahqaf (46), Verse 35
 Ghurar al-Hikam, tr. 4882
 Tadhkeratul Haqa`iq, pg. 86
 Dastan-ha-e-Zindagi-e-~Ali, pg. 97 (a work of this author, published by Intesharat-e-Nasir, Qum);Aine-e-Dil; Manaqib (of Ibn ShahrAshub), vol. 1, pg. 322
 Hikayat-ha-e-Shanidani, vol. 5, pg. 147, Layali al-Akhbar, vol. 1, pg. 266
 Paighambar Wa Yaran, vol. 2, pg. 66; Asad al-Ghabbah, vol. 1, pg. 206
 Muntakhab al-Tawarikh, pg. 51
 Dastan-ha-e-Shigaft, pg. 255