Who are the Ahmadiyyah and why are they dangerous?

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The Ahmadiyyah is a Sufi sect attributed to Ahmad Ar-Rifaa‘i . Shaykh Al-Uloosi said that this sect is the most dangerous of all sects and that it was the source of all religious innovations (in his time). He mentioned that they remember Allaah The Almighty by dancing and that they worship their Shaykhs instead of worshiping Allaah The Almighty.

Ahmad Ar-Rifaa‘i (512-580 A.H) himself, the Shaykh of this Tareeqah, was known to have encouraged his followers to adhere to the Sunnah and avoid religious innovations. He was reported to have said that whenever people are apathetic regarding adherence to the Sunnah and repressing religious innovations, Allaah The Almighty gives their enemy power over them, and that those who adhere to the Sunnah and repress religious innovations are granted dignity and victory by Allaah The Almighty. Nevertheless, the followers of this Tareeqah (order) were notorious for lying about their Shaykh to the extent that the saying goes: Do not say they lie more about Allaah The Almighty than the Jews do, but say they lie more about their Shaykh than the Ahmadis do.

Ibn Taymiyyah mentioned some of the innovations the Ahmadis made in religion and the disputes that took place between him and those people.

Allaah Knows best.