Ruling on marrying a sufi woman
Question

                Is it permissible for a Muslim to marry a Sufi woman? What is the Islamic view of one who married a Sufi woman but he did not know that she was a follower of the Sufi way until after he married her?.
Praise be to Allah.Firstly: 
Sufis are of 
    various kinds with various schools of thought, most of which follow 
    innovation and deviant ways of various kinds. Some of them exceed the proper 
    bounds to the extent of associating others with Allaah, may He be exalted, 
    such as praying to the dead, turning to them to relieve distress and ward 
    off calamity. Some of them follow a great deal of innovation in their deeds, 
    in dhikr and in worship. See question no.
    4983 for more 
    information on some of the deviations of the Sufis, and question no.
    34817 for 
    information on shirk and its types. 
It says in
    Fataawa al-Lajnah al-Daa’imah: Most of those who are called Sufis 
    nowadays follow innovations of shirk, as well as other innovations, such as 
    what some of them say, “Madad ya sayyid (Help, O Master)”and their 
    calling upon the aqtaab (highest ranking awliya’ or “saints”), reciting 
    dhikr in unison and calling upon Allaah by names that He has not called 
    Himself, such as “Huwa Huwa (He, He)” and “Ah, ah (a 
    contraction of the name of Allaah)”. Anyone who reads their books will 
    notice a lot of their innovations of shirk as well as other evils. End 
    quote. 
Secondly: 
Marriage to 
    a Sufi woman is subject to further discussion. 
1 – If she 
    is one of those who commits shirk in belief or in deeds, such as one who 
    believes that the awliya’ (“saints”) have knowledge of the unseen and have 
    control over the universe, or she believes in incarnation of the divine or 
    the unity of all things, or she devotes worship to something other than 
    Allaah, such as du’aa’, seeking help, sacrifices or vows, then it is not 
    permissible to marry such a woman, because she has committed major shirk – 
    Allaah forbid.
2 – If she 
    has not fallen into shirk, but she does some acts of innovation such as 
    celebrating the Mawlid (Prophet’s birthday) or invented forms of dhikr, or 
    reciting a certain number of dhikrs for which there is no basis, or a 
    certain manner of dhikr that is not proven in sharee’ah, then it is better 
    not to marry such a woman, because the danger of innovation is great, and 
    the harm caused by it is severe. It is dearer to Iblees than sin, because 
    one may repent from sin, unlike innovation, for the one who does it regards 
    it as part of religion by means of which he may draw closer to Allaah, so 
    how can he give it up? Moreover, marriage to a woman who follows bid’ah 
    presents a danger to the children and to the whole family, especially if the 
    woman speaks well or is of a good attitude, so that others may be deceived 
    by her. Imam Maalik (may Allaah have mercy on him) said: Do not marry the 
    people of innovation, or give your womenfolk to them in marriage, or greet 
    them with salaam… al-Mudawwanah (1/84). 
Thirdly: 
If he did 
    not know that the woman was a follower of Sufism until he married her, then 
    if she is of the first type that commits shirk in word and deed and belief, 
    he should call her (to the proper way) and advise her and explain to her. If 
    she responds, then praise be to Allaah, otherwise it is obligatory to 
    separate from her, because it is not permissible to marry a mushrik woman or 
    to remain in such a marriage, because Allaah says (interpretation of the 
    meaning): 
“And do 
    not marry Al-Mushrikaat (idolatresses) till they believe (worship Allaah 
    Alone)”

    [al-Baqarah 2:221]
But if she 
    is of the second type, which does some innovated actions that do not reach 
    the extent of kufr, then each case should be examined separately – to what 
    extent does the woman adhere or not to the innovation that she believes in, 
    and what effect will that have on the household and the children? 
He should 
    also look at the consequences of divorcing her, and he should do that which 
    is in the best interests of Islam in each case, and which will ward off harm 
    or reduce it as much as possible. 
May Allaah 
    help us all to do that which He loves and which pleases Him. 
And Allaah 
    knows best.