ISIS being a terrorist organization, even the Islamist gurus are pointing fingers at Nadvi's act. The latter has his own reasons though. According to Nadvi, the letter was a word of advise for the terror group chief so that he could curb the killing of innocent people.
However, religious gurus argue how did Nadvi know that the militant chief would take his advise? They also condemned Nadvi's hailing the chief as 'Amirul Mominin'. "How did he know that he has emerged victorious?" questioned another religious leader.