Are Shias infidels
1: Shia and Sunni are the two major sects of Islam.
2: The division of Shia and Sunni began during the time of the Rightly Guided Caliphs when some of the companions extended their support to Hazrat Ali (RA).
3: From the time of Banu Umayya and then Banu Abbas, differences began to arise among the Shias, and thousands of sects began to form among the Shias.
4: There are different sects among the Shias who expel each other from Shia, Islam, and their own sect.
5: Some sects also formed among the Shias, in which they used to speak out against the Rightly Guided Caliphs and the Mothers of the Faithful.
6: In the eyes of the Sunnis, the Shia are infidels; these are Muslims. There is a difference of opinion among the Sunni scholars on this. The Sunni scholars do not unanimously consider all Shias to be infidels and do not declare them takfir, except for a few sects affiliated with the Shias who deny the requirements of the Rightly Guided Caliphs and the Mothers of the Faithful, such as the Rawafidh Shia sect, which openly expresses its beliefs.
1: 2 The Shia have committed some matters that fall under Shirk which invalidates the foundation of Islam.
But the scholars of Ahlu Sunnah have differed in regards to declaring the general population of the Shia as Kaafirs and classifying them to be out of Islam. And from amongst them are those who have made Takfeer on them (labelled them as Kaafirs), and from amongst them are those who have said that they are not to be made Takfeer upon (not to be labelled as disbelievers) because they are ignorant of the reality of these practices that are classified under Shirk, and so they are not be declared as Kaafirs until it is made clear to them and they realise that what they are doing is Shirk and Kufr.
Book name: Methodological Difference Between ISIS and Al Qaida Who are the ones that deviated?
