Praise be to Allaah.  

1 – Seeking the help of the jinn or turning to them to fulfil one’s desires to cause harm or bring benefit is shirk or associating others in worship with Allaah, because it is a kind of mutual benefitting whereby the jinni responds to the human’s requests and fulfils his needs in return for the human’s veneration of the jinni, turning to him and asking for his help to do what he wants. 

Allaah says (interpretation of the meanings): 

“And on the Day when He will gather them (all) together (and say): ‘O you assembly of jinn! Many did you mislead of men,’ and their Awliyaa’ (friends and helpers) amongst men will say: ‘Our Lord! We benefited one from the other, but now we have reached our appointed term which You did appoint for us.’ He will say: ‘The Fire be your dwelling place, you will dwell therein forever, except as Allaah may will. Certainly your Lord is All-Wise, All-Knowing.’

And thus We do make the Zaalimoon (polytheists and wrongdoers) Awliyaa’ (supporters and helpers) of one another (in committing crimes), because of that which they used to earn”

[al-An’aam 6:128] 

“And verily, there were men among mankind who took shelter with the males among the jinn, but they (jinn) increased them (mankind) in sin and transgression”

[al-Jinn 72:6] 

If a human seeks the help of a jinni to cause harm to another person, or seeks his help for protection from the evil of a person whose evil he fears, all of that is shirk. 

Whoever is like this, his prayer and his fasting are both invalid, because Allaah says (interpretation of the meaning):

 “If you join others in worship with Allaah, (then) surely, (all) your deeds will be in vain, and you will certainly be among the losers”

[al-Zumar 39:65] 

If a person is known for that, then the funeral prayer is not to be offered for him if he dies, his funeral is not to be attended, and he is not to be buried in the Muslim graveyard. 

Fataawa al-Lajnah al-Daa’imah, 1/407, 408 

2 – The Standing Committee was asked a similar question, which said: 

I would like to inform you that in Zambia there is a Muslim men who claims that he has jinn with him, and the people go to him and ask him to heal their diseases, and this jinn prescribes medicine for them. Is that permissible? 

The answer is: 

It is not permissible for that man to use the services of the jinn, and it is not permissible for the people to go to him, seeking treatment for their diseases through advice from the jinn, or to fulfil any needs in this manner. 

Treating disease by means of human doctors and by using permissible medicines means that there is no need for that. This should be enough to free us from the control of these charlatans. 

It was narrated in a saheeh hadeeth that the Messenger (peace and blessings of Allaah be upon him) said: “Whoever goes to a fortune-teller and asks him about something, his prayers will not be accepted for forty days.” (Narrated by Muslim) 

The four authors of al-Sunan, and al-Haakim in a saheeh hadeeth, narrated that the Prophet (peace and blessings of Allaah be upon him) said: “Whoever goes to a fortuneteller and believes what he said has disbelieved in that which was revealed to Muhammad.” 

This man and his companions from among the jinn are to be regarded as fortunetellers and soothsayers. It is not permissible to ask them anything or to believe them. 

Fataawa al-Lajnah al-Daa’imah, 1/408, 409).