Written by brother Saad:
Assalam o alaykum,
Imam Shah ‘Abd al-Aziz Dahlawi (may Allah have mercy on him) has discussed the schemes of ‘Abdullah ibn Saba in great detail in his magnum opus, Tuhfa Ithna ‘Ashariyyah. Son of Imam Sayyid Alusi has translated and abridged it into Arabic.
He writes that ‘Abdullah ibn Saba was a Jew from Yemen and he divided his activates into three different levels depending on the people he was dealing with; hence three different groups emerged through his efforts.
1. At first he claimed the love for Ahl al-Bayt and this was his ploy to gain the sympathies of Muslims. Once he was successful in this he started to claim that Sayyiduna ‘Ali (may Allah be pleased with him) was the most superior after the Holy Prophet (Allah bless him and give him peace). At this point he had attracted a good number of followers. He also forged many narrations in the virtues of Sayyiduna ‘Ali.
Now this is what present day Zaydis hold to. So it is perfectly fine to say that ‘Abdullah ibn Saba was also the founder of Zaydi Shias. These are also known as Tafdilis.
2. Once he was successful in this, he chose a certain number of his followers, those close to him, and started to brainwash them that Sayyiduna ‘Ali was the first Caliph appointed by the Holy Prophet. He told them that it was the Companions (Sahabah) who after the demise of Holy Prophet went against his instructions and usurped the right of Sayyinduna ‘Ali. He was the first one to misinterpret the incident that happened over Fadak and used that as a proof to spread hatred of the Companions. He also made sure to tell his followers that never to ascribe these teachings to him if asked; disassociate from him in public because his purpose is to inform the truth and not fame or power.
Present day Itha ‘Ashariyyah (Twelvers) belong to this second group. They are also known asSabbiyah or Tabarriyah.
3. After this ploy was also successful, he went a step further and selected a certain number of his very close associates and told that that I am about to tell a very sensitive secret. He made them promise that this information will be kept secret. He started off by telling karamat of Sayyiduna ‘Ali and through this he convinced them of Uluhiyyat of Sayyiduna ‘Ali; that Sayyiduna ‘Ali is in fact God but has come in the form of a human.
I believe present day Alawis fall under this category. These are known as Ghullat.
Shah ‘Abd al-Aziz concludes that ‘Abdullah ibn Saba is indeed the founder of above mentioned three groups of Shias. Every single Shia group will fall under one of the above three categories.
As far as the Shia Awla, those were actually Ahl al-Sunnah. They were known as Shia Awla because they sided with Sayyiduna ‘Ali during the differences that arose among various Companions due to the schemes of ‘Abdullah ibn Saba. They had all the beliefs of Ahl al-Sunnah like affirming the superiority of Shaykhayn (may Allah be pleased with them) over Sayyiduna Ali. So it obvious that when it is said, ‘Abdullah ibn Saba is the founder of Shiaism’, Shia Awla are not being referred to. In our time, Shia Awla are referred to as Ahl al-Sunnah wal-Jamah and this title is not used anymore for any given group.