Is it permissible for a Muslim man to marry a Sufi woman, and what is the legal status [in Islamic law] of one who married her without knowing she was a Sufi?

Sufi groups vary in their innovations (bid'ah), with the prevailing characteristic among them being innovation and deviation. The extremism of some may even reach the level of polytheism (shirk), such as invoking the dead. It is not permissible to marry a Sufi woman who commits major shirk, whether in belief or in action. As for one who practices innovations that do not amount to disbelief (kufr), it is preferable not to marry her, due to the danger of innovation to the family and children. If a man marries a Sufi woman and then discovers her true state: if she is a polytheist (mushrikah), he is obliged to call her to the truth; if she does not respond, he is obliged to separate from her. However, if she practices innovations that do not amount to disbelief, then her adherence to her innovations and their effects on the family should be considered, and a balance struck between benefits and harms.