Anyone who claims knowledge of the Ghayb, be it through sand-reading, reading in a certain book, astrology, or seeking the help of the Jinn and the like is considered a soothsayer. It is authentically narrated that the Messenger of Allah (peace be upon him) said,
Anyone who resorts to a soothsayer and believes in what they say has disbelieved in what was revealed to Muhammad.
(peace be upon him) Therefore, it is impermissible to eat from the meat of animals that they sacrifice, to consult them, to accompany them or to shake hands with them. However, it is your duty to guide, advise, and tell them that claiming knowledge of the Ghayb is Kufr (disbelief in Allah) which could take them outside the fold of Islam; may Allah guide them to perform Tawbah (repentance to Allah).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.