Q: Is it permissible to pray behind Sufis?

A: Sufies were, essentially, ascetics who wore only sheep's wool as a demonstration of their self-denial, but later on, they became immersed in innovations, such as dancing, ecstatic trances and (unnatural) relationships with minors. They believe blindly in their Shaikhs from whom they have adopted the belief in pantheism. Therefore, it is not correct to pray behind their leaders, as opposed to the common people among them.

Ibn Jibreen

Adopted from Fatawa Islamiyah Volume 1, First Edition, Page 363