
There is a lie floating around that forces people into believing that only a scholar who is firmly grounded in knowledge is allowed to make Takfeer. This is a lie marketed by the wicked “scholars” because they are afraid that the Ummah will make Takfeer on their Kaafir paymasters.
The Ummah has no choice but to differentiate the Muslims from the Kuffaar because Allah said: "Shall We then treat the (submitting) Muslims like the Mujrimūn (criminals, polytheists and disbelievers, etc.)? What is the matter with you? How judge you?" [68:35-36]
In order to do so, he must be able to know in his heart, that the Kaafir has a false Aqeedah that does not agree with Islam.
If
a Muslim sees a man wearing a cross around his neck he can make Takfeer
on him because to wear a cross is a Christian concept. Therefore, you
don’t have to be an Islamic scholar to make Takfeer on
those who wear the cross. Likewise, if a Muslim hears a man saying the
Qur'an got it wrong because Jesus was crucified, he is allowed to make Takfeer
on this person. He doesn't have to be a scholar to know that a person
who contradicts the Qur'an is a Kaafir. Though yes if someone himself is
in the doubt and isn't aware of the matters of Kuffr and Shirk with
clarity then the person should himself learn first his own Deen before
passing a judgement upon others because indeed Takfeer is not a matter
that should be played around with unless one is fully aware and has no
doubt left.
THE IMPORTANCE OF TAKFEER :
The scholars of Islam have collected many reasons establishing the importance of Takfeer:


