[Aleenkagirlla]

Assalaamu'alaikum brother,

The only reason that human beings may classify each other as 'muslim' or 'non-muslim' is for legal purposes, e.g. one needs to know if a man is a muslim for a muslim woman to be legally permitted to marry him. Thus the label of kufr is simply for us to be able to define our interactions with other people.

Calling people non-muslims for the purpose of 'damning' them, saying people who sin are non-muslims etc or claiming that such and such people are going to go to hell, is not permissible. If someone says the shahadah, they remain a Muslim even though they may sin, unless they hold true things which are untrue as defined by the scholars of ahl al-sunnah wa'l jama'ah, e.g. ahmadiyya who claim another prophet after nabiyyina Muhammad (saw), or people who claim something haram to be permissible etc.

In the case of Shi'as, their doctrines contain blameworthy innovations and some among them do hold beliefs that are considered to be kufr, e.g. that 'Ali should have been the Prophet (astaghfirullah) and these specific people are held by scholars to be non-Muslim. However most Shi'as are still considered Muslims but are مبتدعون (mubtadi'un - innovators) as they have introduced innovations into the deen.

However, at the end of the day, only Allah knows whether someone is a true Muslim or not as this depends on their sincerity and on the state of their heart, which no other human being will ever know. Thus we shouldn't go around condemning people. A lot of Muslims have these bad habits of being quite self-righteous and not actually knowing much about the details of the deen...

"If a man calls his Muslim brother kafir, it applies to one of the two." (Bukhari)

Wallahu a'lam