Is Sufiism related to Islam? What is the concept of Sufiism?
Sufism is related to Islam. It is a deviant stream flowing from Islamic teachings. Its main issue of deviance is that it promotes intermediacy. It places intermediaries between man and God. It promotes praying to these intermediaries as the most effective way to reach God. The intermediaries are called Awliyaa, or saints, and are used quite similarly to Catholics who pray to their saints or through them. The Shia also share this same deviation, only their intermediaries are the 12 (or 7 or 5) Imaams. They (Shia) also pray to Faatimah, daughter of the Prophet (ﷺ) and to the Prophet himself. 
 Sheikh A Tabari, The Other side of Sufism, p 4< Back to Questions