Virtues of the Sahabah (Prophet’s Companions)
Question

I hope that you can explain the virtues of the Sahabah and what distinguishes them from others?
Praise be to Allah.Virtues of the Sahabah
Belief in the good character and virtue of the Sahabah is the belief of Ahl al-Sunnah wal-Jama`ah . That is because Allah has praised them in His Book and they were also praised by the Prophet (peace and blessings of Allah be upon him) as is narrated in the books of Sunnah. 
These texts reach the level of mutawatir in many cases, which clearly indicates that Allah gave them special virtues and noble characteristics, by means of which they attained that great honour and high status with Him. 
As Allah chose for His message the most pure-hearted of His slaves (i.e., the prophets), so too He chose as the heirs of the prophets those who would be grateful for this blessing and who were fit for this honour (of conveying the message), as He says (interpretation of the meaning): 
“Allah knows best with whom to place His Message.” [Al-An’am 6:124]
Ibn al-Qayyim (may Allah have mercy on him) said: 
“Allah knows best where to place His Message, both with regard to the original recipient and those who inherit it from him. He knows best who is fit to receive His Message and convey it to His slaves in a trustworthy and sincere manner, respecting the Sender and fulfilling his duties towards Him, patiently following His commands and showing gratitude for His blessings and drawing close to Him, and He knows who is not fit for that. Similarly, He knows best who among the nations is fit to be the heirs of His messengers and to succeed them and convey the Message that they received from their Lord.” (Tariq al-Hijratayn, p. 171) 
Allah says (interpretation of the meaning): 
“Thus We have tried some of them with others, that they might say: ‘Is it these (poor believers) whom Allah has favoured from amongst us?’ Does not Allah know best those who are grateful?” [Al-An’am 6:53]
Shaykh al-Sa’di (may Allah have mercy on him) said: 
“Those who acknowledge the blessing and affirm it, and who do what it requires of righteous deeds , are the ones on whom Allah bestows His blessing, to the exclusion of those who are not grateful, for Allah is wise and He does not place His bounty with one who is not qualified to receive it. 
Just as there are many verses and hadiths which speak of their virtue and high status, so too there are texts which state the reasons why they deserved this high status, such as the verse in which Allah says (interpretation of the meaning): 
“Muhammad is the Messenger of Allah. And those who are with him are severe against disbelievers, and merciful among themselves. You see them bowing and falling down prostrate (in prayer), seeking Bounty from Allah and (His) Good Pleasure. The mark of them (i.e. of their Faith) is on their faces (foreheads) from the traces of prostration (during prayers). This is their description in the Tawrat (Torah). But their description in the Injil (Gospel) is like a (sown) seed which sends forth its shoot, then makes it strong, and becomes thick and it stands straight on its stem, delighting the sowers, that He may enrage the disbelievers with them. Allah has promised those among them who believe (i.e. all those who follow Islamic Monotheism, the Religion of Prophet Muhammad till the Day of Resurrection) and do righteous good deeds, forgiveness and a mighty reward (i.e. Paradise)” [Al-Fath 48:29]
Among the greatest reasons for the high status of the Companions is that to which Allah bore witness of their purity of heart and sincere faith. That, by Allah, is a mighty testimony from the Lord of mankind, which no human being can attain after the cessation of the Revelation. 
Listen to the words of Allah (interpretation of the meaning): 
“Indeed, Allah was pleased with the believers when they gave the Bay‘ah (pledge) to you (O Muhammad) under the tree, He knew what was in their hearts, and He sent down As-Sakinah (calmness and tranquillity) upon them, and He rewarded them with a near victory.” [Al-Fath 48:18]
Ibn Kathir (may Allah have mercy on him) said in Tafsir al-Quran al-‘Adhim (4/243): 
“He knew what was in their hearts” i.e., of sincerity and loyalty, and the willingness to hear and obey.”
How beautiful are the words of ‘Abd-Allah ibn Mas’ud (may Allah be pleased with him): 
“Whoever among you wishes to follow (someone), let him follow one who has died, for the one who is still alive is not safe from fitnah. The Companions of Muhammad (peace and blessings of Allah be upon him) were the best of this ummah, the most righteous of heart and the deepest in knowledge and the most straightforward, people whom Allah chose to accompany His Prophet and establish His Religion. So acknowledge their virtue and follow in their footsteps, and adhere as much as you can to their morals and Religion, for they were following right guidance.  (Narrated by Ibn ‘Abd al-Barr in al-Jami’, no. 1810)
Allah promised Paradise and eternal bliss to the Muhajirin and Ansar , and He stated that He is pleased with them in verses that will be recited until the Day of Resurrection. Can anyone think that this would be given to one who does not deserve that bounty? 
Allah, may He be glorified and exalted says (interpretation of the meaning): 
“And the foremost to embrace Islam of the Muhajirun and the Ansar and also those who followed them exactly (in Faith). Allah is well-pleased with them as they are well-pleased with Him. He has prepared for them Gardens under which rivers flow (Paradise), to dwell therein forever. That is the supreme success.” [Al-Tawbah 9:100]
The leader of mankind, the foremost among the messengers and prophets, also testified to their virtue. He was a witness over them during his lifetime; he saw their sacrifices and their sincere resolve, and he (peace and blessings of Allah be upon him) spoke immortal words of the honour of his Companions and his love for them.  
It was narrated from Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: “Do not revile my Companions, for by the One in Whose Hand is my soul, if one of you were to spend the equivalent of Uhud in gold, it would not amount to a mudd of one of them, or half of that.” (Narrated by al-Bukhari (3673) and Muslim (2540) 
It was narrated from ‘Abd-Allah ibn Mas’ud (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “The best of the people are my generation, then those who come after them, then those who come after them.” (Narrated by al-Bukhari (2652) and Muslim (2533) 
Al-Khatib al-Baghdadi (may Allah have mercy on him) said in al-Kifayah (49): 
“Even if there was nothing narrated from Allah or His Messenger about them, the things that they did such as migrating (hijrah), engaging in jihad, supporting (the Prophet (peace and blessings of Allah be upon him) and Islam), expending their lives and their wealth, killing their fathers and sons (in jihad), sincerely following the Din, believing strongly and with certainty, is definitive proof of their good character and sincerity, and shows that they are superior to all those sincere people of good character who come after them, for all time. This is the view of all the scholars, and of the fuqaha whose opinion counts.”
If we were to list the attitudes with which they supported the Religion and the righteous deeds by means of which they deserved that high status, we would fill volumes. Their whole lives were spent for the sake of Allah and what book is big enough to contain the lives of hundreds of the Sahabah who filled the world with goodness and righteousness? 
Ibn Mas’ud (may Allah be pleased with him) said: 
“Allah looked into the hearts of His slaves, and He saw that the heart of Muhammad (peace and blessings of Allah be upon him) was the best of people’s hearts, so He chose him for Himself and sent him with His Message. Then He looked into the hearts of His slaves after the heart of Muhammad, and He found that the hearts of his Companions were the best of people’s hearts, so He made them the supporters of His Prophet, who fought for His Religion. So whatever the Muslims think is good, is good before Allah, and whatever they think is bad, is bad before Allah.” (Narrated by Ahmad in al-Musnad (1/379). The scholars of hadith said: Its isnad is hasan. 
That is also discussed in detail in the answers to questions no. 13713  and 45563 . 
Were the Sahabah infallible?
It is essential to understand that the Sahabah were not infallible. This is the view of Ahl al-Sunnah wal-Jama`ah. Rather they were human beings like any others.  
Whatever sins or mistakes any of them may have made may be overlooked in comparison to the honour of accompanying the Prophet (peace and blessings of Allah be upon him) and they were forgiven and pardoned. Good deeds take away bad deeds. The support that the Companions gave to the Prophet (peace and blessings of Allah be upon him) at any given moment for the sake of this Religion cannot be matched. 
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:  
“Ahl al-Sunnah speak well of them, and pray for mercy and forgiveness for them, but they do not believe that anyone is infallible or that anyone is protected from making mistakes in their ijtihad except the Messenger of Allah; it is possible for anyone else to commit sins or make mistakes, but they are as Allah says (interpretation of the meaning): 
“They are those from whom We shall accept the best of their deeds and overlook their evil deeds. (They shall be) among the dwellers of Paradise ___ a promise of truth, which they have been promised” [Al-Ahqaf 46:16].
The virtue of any deeds is to be judged by the results and consequences.” (Majmu’ al-Fatawa, 4/434) 
This is confirmed in the Quran and Sunnah, in more than one place. 
Allah forgave those of the  Companions who turned back on the day of Uhud, as He says (interpretation of the meaning): 
“Those of you who turned back on the day the two hosts met (i.e. the battle of Uhud), it was Shaytan (Satan) who caused them to backslide (run away from the battlefield) because of some (sins) they had earned. But Allah, indeed, has forgiven them. Surely, Allah is Oft-Forgiving, Most Forbearing.” [Aal ‘Imran 3:155]
When one of the  Companions sinned by telling Quraysh that the Prophet (peace and blessings of Allah be upon him) was coming with the army during the year of the Conquest, and ‘Umar ibn al-Khattab wanted to execute him, the Prophet (peace and blessings of Allah be upon him) said: “He was present at Badr, and you do not know, perhaps Allah looked upon the people of Badr and said: ‘Do what you wish, for I have forgiven you.’”  (Narrated by al-Bukhari and Muslim (2494) 
And there are other cases in which some of the  Companions committed sins, then Allah, may He be exalted, pardoned them and forgave them, which is indicative of their virtue and honour and that cannot be undermined by any mistake that they made during the time of the Prophet (peace and blessings of Allah be upon him) or after he died. The verses quoted above, which speak of their virtue and give them the glad tidings of Paradise, cannot be abrogated by anything.
For more, please see these answers: 223036 , 14488 , 260366 ,223036 and 187715
And Allah knows best.