Shaikh-ul-Islam Muhammad bin Abdul-Wahhab stated, “Know that ten matters negate one’s Islam. [They are:]
“First, associating partners in the worship of Allah. Allah says, “Verily, Allah forgives not (the sin of) setting up partners in worship with Him, but He forgives whom He pleases other sins than that” (al-Nisa 116).
Allah also says, “Verily, whosoever sets up partners in worship with Allah, then Allah has forbidden Paradise for him, and the Fire will be his abode. And for the wrongdoers, there are no helpers” (al-Maidah 72).
Included in this category of deeds is sacrificing animals for the sake of jinn or graves.
“Second, whoever sets up an intermediary between himself and Allah, whom he prays to, seeks intercession from and puts his reliance in, has blasphemed according to the consensus of the scholars.
“Third, whoever does not consider the polytheists as disbelievers or whoever has doubt concerning their disbelief or whoever considers their way as correct has committed an act of disbelief himself.
“Fourth, if a person believes that some guidance other than the guidance of the Prophet (peace be upon him) is more complete than his or that another’s judgment is better than the Prophet’s, [then that person has committed an act of disbelief]. This would be like the one who prefers the rule and law of false gods [be they human or otherwise] over the Prophet’s rule and law. This position is one of disbelief.
“Fifth, whoever dislikes anything the Prophet (peace be upon him) brought, even if he acts by it, has committed an act of disbelief.
“Sixth, whoever ridicules or jokes about any part of the religion of the Messenger (peace be upon him) or its rewards or its punishments, has committed an act of disbelief. The evidence for this is in the Words of Allah, “Say: Was it Allah, or His signs or His Messenger that you were mocking? Make no excuse, you have disbelieved after you had believed.” (al-Tauba 65-66).
“Seventh, the performing of magic [is an act of disbelief], this includes those magical incantations that make one love or hate another person. Whoever performs them or is pleased with them has committed an act of disbelief. Allah says in the Quran, “But neither of these two (angels) taught anyone (such things) until they had said, ‘We are only for trial, so disbelieve not [by learning such magic from us]”’ (al-Baqara 102).
“Eighth, assisting and supporting the polytheists against the Muslims [is also a type of disbelief ]. The proof for this is in Allah’s statement,
"And if any among you takes them [the Jews and Christians] as helpers and protectors, then surely he is one of them. Verily, Allah guides not those people who are wrongdoing” (al- Maida 51).
“Ninth, if a person believes that some people are permitted to be free of the Law of Muhammad (peace be upon him), in the same way that Khidr was free of the law of Moses (peace be upon him), then that person is a disbeliever.
“Tenth, turning away from the religion of Allah, not learning it or applying it, [is also a form of disbelief ]. The evidence for this is Allah’s saying,
"And who does more wrong than he who is reminded of the signs of his Lord, then he turns aside therefrom? Verily, We shall exact retribution from the sinners “ (al-Sajdah 22).
"There is no difference with respect to all of the above whether the act is done jokingly, seriously or out of fear. The only exception is one who is coerced. All of them are from the greater of the dangerous acts and they are also among the most common in occurrence. A Muslim must be aware of them and fear for himself concerning such actions. We seek refuge in Allah from that which brings about His anger and the painfulness of His punishment
Islamvermont.com: In case some have committed any of the sins mentioned above, they should sincerely repent for their sins and ask Allah for forgiveness, and never commit same.
We as Muslims need to educate ourselves of these matters, so that we do not commit such sins.