The Soothsayers Are The Messengers of Satan
Ibn al-Qayyim has written,
Fortunetellers and soothsayers are messengers of Satan. This is so because the polytheists hasten to them. They rush to them in anticipation when anything important is happening and they believe in their words. They take them as the decider of their affairs and they are pleased with their rulings. This is the same behaviour that the followers of the messengers [of Allah] have towards the messengers. They believe that [these fortune tellers] have knowledge of the unseen things that no one else knows about. So for the people who make idolatry through them, they are in the place of messengers. In reality, the fortune tellers and soothsayers are truly the messengers of Satan. He sends them to his party of polytheists and makes them appear like truthful messengers until his party responds to them in order to take them away from the messengers of Allah. They consider their messengers to be truthful ones who have knowledge of the unseen. Since there is such a great difference and contradiction between the two, the Messenger of Allah (peace be on him) said, “Whoever goes to a fortune-teller and believes in what he says he has disbelieved in what has been revealed to Muhammad”.
So people are of two categories: followers of the fortune-tellers and followers of the [true] messengers [of Allah]. One person cannot be of both the latter and the former. In fact, the further he goes from the Messenger by the amount that he believes in the fortune-teller.
Ibn al-Qayyim, Ighaatha al-Luhfaan, vol. 1, p. 271