Assalam 3alaykoum
The statements which comply with the laws of the Religion are the sound sayings, whereas the sayings which contradict the Religion are abhorrent and evil. With reference to Sufism, the sound saying which complies with the laws of the Religion is that Sufism is the methodology implemented by the true Sufis and is very much a part of the Religion.
True Sufis are people who
realize the importance of the Obligatory Knowledge of the Religion and endeavor to acquire it through proper channels, i.e., through trustworthy and knowledgeable teachers. They acquire the knowledge,
then implement it and encourage others to do the same. Sufis are a people who follow the great Messenger, Muhammad, in a full manner by following his teachings and his example. They weigh things by the scale of the Religion. They do not deem lawful that which Allah ordained as unlawful, and they do not deem unlawful that which Allah ordained as lawful. They judge ugly what the laws of the Religion judge ugly, and they judge good what the laws of the Religion judge good. They do not indulge their appetites, and do so willingly. They go against the desires of their selves. They are a people who keep busy worshipping their Lord, fighting laziness and ignorance. They may work in the matters of this life, yet they do not have an interest in worldly acquisitions because the world has departed their hearts.
Beware of suficlaimers. these are not Sufis and have bad intentions. Anyone who claims that Allah is a body that fills the space around us, or that He becomes a part of the man or inhabits the man, or that He sits on the Throne is a blasphemer not a Muslim and not a Sufi. Some Suficlaimers these days say that they become one with Allah, that Allah is in them, and that is blasphemy. beware of searching the internet all by yourself if you lack knowledge, and reading all by yourself their sick websites (I read many that contain blasphmy) becasue you might be lost if you didn't learn the rules of the religion...
For more information please read the three parts in this lesson
http://www.aicp.org/IslamicInformation/English/SUFISMvsSUFICLAIMERS.htmwassalam