Deserting one's relatives dealing with magicians and diviners
12-9-2011 | IslamWeb
Question:
Is it permissible for me to desert my relatives because they deal with sorcerers and soothsayers?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
Dealing with sorcerers and soothsayers is a major sin, as the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said that a person who goes to a soothsayer or a diviner and believes him, disbelieves in what was revealed to Muhammad 
. [Ahmad]
Moreover, the Sunnah (Prophetic tradition) proves that deserting sinners until they repent is lawful, as the Prophet, sallallaahu ‘alayhi wa sallam, deserted his three Companions who abstained from participating in the Battle of Tabook without excuse. Nevertheless, Sharee‘ah-considered interests should be observed.
Consequently, if severing ties with these relatives will deter them from dealing with sorcerers and soothsayers, then you should do this. However, if maintaining your relations and calling them to Allaah The Almighty through wisdom and sound reasoning may lead them to repentance, then it is better not to sever your ties with them, provided that no harm befalls you.
If both cases are the same, i.e., they will not refrain from dealing with sorcerers whether you desert them or not, then it is better to sever your relations with them, because a Muslim is commanded to enjoin what is good and forbid what is evil, as far as he can. This includes severing ties with the person who commits Munkar (evildoing) until he refrains and repents, providing that breaking relations does not lead to almost certain evil.
Samurah ibn Jundub 
was told that his son kept eating until he could not sleep. He said that if his son died because of this he would not offer the funeral prayer for him because he had harmed himself. [This narration was mentioned by Shaykh Al-Islam Ibn Taymiyyah in Al-Fataawa]
Thus, if the son who ate so much that he died deserved to be deserted, despite the fact he did not intend to kill himself, then the person who deals with sorcerers and soothsayers deserves to be deserted with greater reason.
Allaah Knows best.