Reply: According to the Shi‘ah, those who happened to meet and accompany the Prophet (S) can be divided into some groups. Before explaining this statement in detail, we had better define the word, “sahabi” {companion}.
There are various definitions of the word “Companion” of the Prophet (S). Below are some of them:
1. Sa‘id ibn Musayb says: “Sahabi is referred to the person who kept company with the Prophet for one or two years and fought alongside him one or two battles.”
2. Waqidi says: “Scholars are of the opinion that whoever saw the Prophet, embraced Islam, thought of the religion, and was pleased with it, even if that was for only one hour, is regarded as among the Companions of the Prophet.”
3. Muhammad ibn Isma‘il al-Bukhari states: “Any Muslim who accompanied the Prophet and saw him is regarded as one of his Companions.”
4. Ahmad ibn Hanbal says: “Anyone, who accompanied the Prophet for a month, a day or an hour, or saw him, is considered among the Companions.”
Some of the ‘ulama’ of Ahl as-Sunnah acknowledge that the justice of the Companions is an indisputable principle in the sense that whoever kept companionship with the Prophet (S) is just!
Now, taking into consideration the explicit verses of the Qur’an, we shall examine this statement to point out the Shi‘ah viewpoint which is derived from the logic of revelation: History has recorded the names and descriptions of more than 12 thousand people as the Companions of the Prophet (S) including people of various personalities. The station of companionship of the Prophet is, without doubt, a great honor granted to a certain group, and the Muslim ummah always holds the Companions in high esteem because they are the first group of Muslims to hoist Islam’s banner of glory and grandeur.
The Holy Qur’an also hails those pioneering standard-bearers (of Islam), stating:
“Not equal {to others} are those of you who spent and fought before the victory. They are greater in rank than those who have spent and fought afterward.”
We should also confess that the companionship of the Prophet of God is not an alchemy that transforms man’s disposition, ensures his piety throughout his life or causes him to be one of the just.
In order to clarify this point, it is worth concentrating on the Qur’an, which is accepted by the Muslims all over the world, and resort to this sacred book for solving this issue:

Sahabi {Companion} from the viewpoint of the Qur’an
In the logic of revelation, those who happened to meet the Holy Prophet (S) and accompany him are divided into two groups:

The first group
The people of this group are hailed and praised by the everlasting verses of the Qur’an and described as the founders of the castle of the glory and grandeur of Islam. The following are some of the Qur’anic verses regarding this group of the Companions:

1. The first followers
“The early vanguard of the Emigrants and the Helpers and those who followed them in virtue- Allah is pleased with them and they are pleased with Him, and He has prepared for them gardens with streams running in them, to remain in them forever. That is the great success.”

2. Those who swore allegiance under the tree
“Allah was certainly pleased with the faithful when they swore allegiance to you under the tree. He knew what was in their hearts, so He sent down composure on them, and requited them with a victory near at hand.”

3. The Muhajirun {Emigrants}
“{They are also} for the poor Emigrants who have been expelled from their homes and {wrested of} their possessions, who seek grace from Allah and {His} pleasure and help Allah and His Apostle. It is they who are the truthful.”

4. The Companions who fought alongside the Prophet (S)
“Muhammad, the Apostle of Allah, and those who are with him are hard against the faithless and merciful among themselves. You see them bowing and prostrating {in worship}, seeking Allah’s grace and {His} pleasure. Their mark is {visible} on their faces, from the effect of prostration.”

The second group
The other group of those who accompanied the Prophet (S) consist of two-faced and sick-hearted men the reality of whose nature the Holy Qur’an has revealed and of whose danger it has warned the Prophet (S). Here are some examples of this group:

1. Known hypocrites
“When the hypocrites come to you they say, ‘We bear witness that you are indeed the apostle of Allah.’ Allah knows that you are indeed His Apostle, and Allah bears witness that the hypocrites are indeed liars.”

2. Unknown hypocrites
“There are hypocrites among the Bedouins around you and among the townspeople of Madinah, steeped in hypocrisy. You do not know them; We know them, and We will punish them twice, then they shall be consigned to a great punishment.”

3. Sick-hearted ones
“And when the hypocrites were saying, as well as those in whose hearts is a sickness, ‘Allah and His Apostle did not promise us {anything} except delusion’.”

4. Sinners
“{There are} others who have confessed to their sins, having mixed up righteous conduct with other that was evil. Maybe Allah will accept their repentance. Indeed Allah is all-forgiving, all-merciful.”
In addition to the noble verses of the Qur’an, many traditions have been narrated regarding the Holy Prophet’s (S) reproaching some of the Companions. We shall cite two examples:
1. Abu Hazim narrates on the authority of Sahl ibn Sa‘d that the Holy Prophet (S) is reported to have said:
I will send you toward the Pool; whoever comes upon it will drink from it, and whoever drinks from it will no longer feel thirsty. There will come to me some people; I know them and they know me, but they will be separated from me.
Abu Hazim has said: “While I was narrating this hadith, Nu‘man ibn Abi ‘Ayyash heard it and asked me, ‘Did you hear it from Sahl like that?’ I said, ‘Yes’. He said: ‘I bear witness that Abu Sa‘id al-Khudri says that the Prophet has also said’:
“They are from me.” Then someone says, “You do not know what they did after you!” So I shall say, “Damn those who have changed (the truth) after me.”
It is obvious that such words like, “I know them and they know me,” or, “Damn those who have changed (the truth) after me,” refer to the Companions of the Prophet (S) who were in his company for a time. This hadith has also been narrated by al-Bukhari and Muslim.
2. Al-Bukhari and Muslim narrate that the Prophet (S) is reported to have said:
On the Day of Resurrection, a group from among my Companions - (or, “my ummah”) shall come to me but they shall be prevented from reaching the Pool (of Kawthar). Then, I shall say, ‘O Lord! They are my Companions.’ Then He shall say, ‘You do not know what they did after you; they returned to their former state (state of jahiliyyah or ignorance)’.”

Conclusion
From the Qur’anic verses and Sunnah of the Prophet (S), it is clear that the Companions of the Prophet (S) and those who accompanied him were of more than one type or category; a group of them were refined men at the apex of merit whose valuable services led to the fruition of the nascent bud of Islam and another group composed of individuals who were two-faced, hypocrites, sick-hearted, and sinners from the very beginning.
The aforementioned observations make clear that the view of the Shi‘ah regarding the Companions of the Prophet (S) is the same as that of the Book of God and the Sunnah of the Prophet (S).