Answered by Shaykh Faraz Rabbani
Why do you say that Shias are Muslims?
I know that some of them are Muslims (the Zaydis), but the majority of them (from the looks of it) are kaafirs (the Ismailis, Nusayris, a lot of the Ithna Asharis).
They say that Aisha (ra) committed adultery, that the companions turned apostate, that their Imams are superior to the prophets, that the Quran is incomplete, that Angel Jibreel made a mistake by going to Muhammad (saw) and was supposed to go to Ali (ra). They also worship Ali and others.
As for the Amman Message, they only declared the validity of the Zaydi and the Jafari sects of Shiism. There are other Shia sects too, and the Amman Message did not declare them to be valid. I saw many muftis online do takfir of other Shia sects.
I hope you’re doing well, insha’Allah.
None of the four Imams declared the Twelver Shias to be outright disbelievers. [Ibn Abidin, Radd al-Muhtar]
Anyone who denies what is necessarily known to be of the religion (al-ma‘lum min al-din bi l-darura) is a disbeliever. [ibid; Bajuri, Tuhfat al-Murid ‘ala Jawharat al-Tawhid; Nabulsi, Sharh Ida’at al-Dujunna]
We distance ourselves from innovation (bid’a), maintain good relations with principle and wisdom, and avoid sectarianism and anything that stirs communal strife (fitna), which is the playground for the Devil, egos, and the enemies of religion.
The soundness of beliefs and practices is a different matter, of course. By definition, Ahl al-Sunna considers those outside of the boundaries of Sunni Islam to be in error in those beliefs or practices outside the consensus of acceptability.
My advice is to focus on what benefits you; learn your faith and practice soundly; keep away from sectarianism and polemics; and maintain good opinion and good relations with all people–especially fellow Muslims, even if we may disagree with them–with principle, good character, and wisdom.
And Allah is the giver of success and facilitation.
[Shaykh] Faraz Rabbani
Shaykh Faraz Rabbani spent ten years studying with some of the leading scholars of recent times, first in Damascus, and then in Amman, Jordan. His teachers include the foremost theologian of recent times in Damascus, the late Shaykh Adib al-Kallas (may Allah have mercy on him), as well as his student Shaykh Hassan al-Hindi, one of the leading Hanafi fuqaha of the present age. He returned to Canada in 2007, where he founded SeekersGuidance in order to meet the urgent need to spread Islamic knowledge–both online and on the ground–in a reliable, relevant, inspiring, and accessible manner. He is the author of: Absolute Essentials of Islam: Faith, Prayer, and the Path of Salvation According to the Hanafi School (White Thread Press, 2004.) Since 2011, Shaykh Faraz has been named one of the 500 most influential Muslims by the Royal Islamic Strategic Studies Center.