What are the circumstances of people going to soothsayers and what is the ruling of Islam on each?

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 ‘alayhi wa sallam, is His slave and Messenger.

The Sharee‘ah ruling of the person who goes to a soothsayer or a diviner varies according to his intention which could be one of  three cases:

The first is the person who goes to a soothsayer, believes his words and believes in his 'ability' to know the Unseen. According to the scholars’ consensus, this person is committing an act that results in apostasy because he is associating others with Allaah The Almighty in the knowledge of the Unseen - which only Allaah The Almighty knows. He Says (what means): {Say, none in the heavens and earth knows the unseen except Allaah.}[Quran 27:65] Moreover, this person is identified as a disbeliever. This is because by doing what he does, he has also denied the affirmation of the Prophet, sallallaahu ‘alayhi wa sallam , that such people are liars.

In a Hadeeth on the authority of Abu Hurayrah the Prophet, sallallaahu ‘alayhi wa sallam, informed us that whoever goes to a soothsayer or a diviner and believes what he says becomes a disbeliever. [Ahmad and Al-Haakim] However, scholars have different opinions regarding the person who goes to a soothsayer, believes what he says but knows that he cannot perceive the Unseen and that he takes his information either from the Jinns who steal information or the Jinn who accompanies man. Some of them say that this is still an act that results in apostasy, whereas others say that this is a contradiction of faith but one of the grave major sins (and not outright apostasy).

The second case is the person who goes to a soothsayer but does not believe what he says. This person is not committing an act of disbelief, yet he is committing a grave major sin and for forty days he will not be rewarded for his prayers. This is supported by a Hadeeth on the authority of some of the wives of the Prophet, sallallaahu ‘alayhi wa sallam, where he mentioned that the one who goes to a diviner to ask him about anything will not have his prayers accepted for forty nights. [Muslim and Ahmad]

The third case is when a person goes to a soothsayer only to prove to people that he is a liar or to rebuke him for what he is doing. In this case, it is permissible and the person who does it is rewarded. Furthermore, it becomes a must on the one who can do so because it is classified under the duty of enjoining good and forbidding evil.

Allaah Knows best.