In the earlier years of Islam, the Muslim ummah itself divided themselves into three categories in regards to how they viewed the sahabah:
(1) Al-Firqa al-Kamiliyah and the Ghulat
They were a minority sect of Muslims that attributed kufr (apostasy) to all of the companions. This view is of course, completely rejected by all modern scholars of Islam, in both the Sunni and Shia traditions.
(2) Adalat al-Sahabah – Integrity of the Companions
This group attributed absolute adalah (integrity) to all of the companions; this is the commonly held view within the Sunni tradition. For example, Al-Khatib al-Baghdadi says, “The justness of the sahabah is proven and firmly established (thabitatun malumah).” Ibn Hazm says, “Undoubtedly, all of the companions are among the people of Paradise.”
Nevertheless, many prominent jurists and scholars in the Sunni tradition reject this idea of the absolute righteousness of all of the companions, and they include: al-Sa’d al-Tafatahzani, al-Marizi, and al-Shawqani, as well as scholars from a later generation, such as Sheikh Muhammad Abduh, Sheikh Mahmud Abu Riyah, and others. They argued that the companions were not infallible, and thus there were the righteous and the unrighteous individuals amongst their ranks.
(3) The Qur’an, the Prophet, and the Ahlul Bayt
The Qur’an does not guarantee automatic righteousness to all of the Prophet’s companions, nor does it grant all of them entrance into Paradise. Many of the righteous companions are praised and honored in the Qur’an, while others have been criticized – even cursed. The Qur’an says, “Round about you [Muhammad and his community] and among you in Madinah are hypocrites and they are obstinate in hypocrisy. You do not know them, We know them, twice shall We punish them and in addition they shall be sent to a grievous penalty.” (c. 9:101) The Qur’an also says, “And Muhammad is not but an apostle, (other) apostles have already passed away prior to him; therefore, if he dies or is slain, will you turn upon your heels? And he who turns upon his heels will by no means do harm to God in the least, and soon will God reward the grateful ones.” (c. 3:144) These and others verses, such as those found in Surah al-Tawbah (Repentance) and Surah al-Munafiqun (The Hypocrites) indicate that a group of hypocrites existed among the companions of the Prophet. Thus, according to the Qur’an, a group of companions was composed of the righteous and the unrighteous, the believers and the hypocrites, and although companionship was a great honor, it did not ensure immunity from error and this view has been adopted by the Shia scholars as well.
In many of the hadith, the companions themselves rejected each other or refuted what other companions said. As for the leaders of the Islamic schools of thought, Imam Abu Hanifah is known to have said that all of the companions were pure except for a few, and he mentioned some of their names. Imam Malik b. Anas was asked what to do when two narrators relate contradictory hadith from the Prophet and whether both should be accepted or not? He replied that, no, the truth is only one; and when he was asked about the disagreement of the companions (ikhtilaaf al-sahabah), he said that one side is right and the other is wrong, and that the matter had to be investigated. Imam al-Shaf’i states that he does not accept the testimony of four known companions: Mu’awiyah b. Abu Sufyan, Amr b. al-Aas, al-Mugheerah, and Ziyad.
 The Kamilites – one of the schools of thought in Islamic theology.
 Those who attributed divinity to certain individuals.
 Ibn Hajar, al-Isabah, 1:17
 Ibn Hajar, al-Isabah, 1:19; Ibn Abd al-Birr, al-Estiaab, 1:8; Ibn al-Atheer, Usd al-Ghabah, 1:3
 Al-Sa’d al-Tafatahzani, Sharh al-Maqasir, 5:310; al-Marizi, al-Isabah, 1:19; al-Shawqani, Irshad al-Fuhul
 Sheikh Muhammad Abduh, Adwa ala al-Sunnah Muhammadi; Sheikh Mahmud Abu Riyah, Abu Huraira, 1:01
 Ibn Abil Hadid, Sharh Nahjul-Balaghah
 Ibn Abd al-Birr, Jami Bayan al-Ilm
 Abul Fida, al-Mukhtasar fi Akhbar al-Bashar