But if the aim is to warn against him and guard against his harm, less evidence than that suffices. As ʿAbd Allāh ibn Masʿūd said, “Judge people by their close companions.” When ʿUmar ibn al-Khattāb—may Allah be pleased with him—was informed that young men were gathering around a certain man, he forbade keeping company with him. Thus, if a man associates with evildoers in the course of his affairs, people should be warned against him.

“One who calls others to religious innovation” deserves punishment by the consensus of the Muslims. His punishment may sometimes be execution and sometimes a lesser penalty, just as the early Muslims executed Jahm ibn Safwān, al-Jaʿd ibn Dirham, Ghaylān al-Qadarī and others. Even supposing that he does not deserve punishment, or that punishing him is not possible, his innovation must nevertheless be exposed and people warned against it. This is part of enjoining what is right and forbidding what is wrong, which Allah and His Messenger have commanded.

The “religious innovation” by which a person is counted among the adherents of deviant beliefs is one whose opposition to the Quran and Sunnah is well known among scholars versed in the Sunnah. Examples include the innovations of the Khawārij, the Rāfidah, the Qadariyyah and the Murjiʾah. For ʿAbd Allāh ibn al-Mubārak, Yūsuf ibn Asbāt and others said:

“The seventy-two sects stem from four principal groups: the Khawārij, the Rāfidah, the Qadariyyah and the Murjiʾah.”

Ibn al-Mubārak was asked, “What about the Jahmiyyah?”

He replied, “The Jahmiyyah are not part of the community of Muhammad—may Allah bless him and grant him peace.”

The “Jahmiyyah” are those who deny the divine attributes. They say that the Quran is created, that Allah will not be seen in the Hereafter, that Muhammad was not taken up to Allah, and that Allah has neither knowledge, nor power, nor life, and other such things, as maintained by the Muʿtazilah, the philosophers and their followers.