The person who proclaim that he is Prophet after Rasoollallah Saw is comitting Kufr and so leaving the deen of islam .
Apostasy in Islam
Apostasy in Islam (
Arabic: ردة
riddah, literally means: "
relapse" or "
regress" but usually translates to "
apostasy", or ارتداد
irtidād) is commonly defined in
Islam as the rejection in word or deed of one's former religion (
apostasy) by a person who was previously a follower of Islam. Islamic scholarship differs on the appropriate punishment for the apostate (or murtad مرتد ), which ranges from
execution – based on an interpretation of certain
hadiths – to no punishment at all as long as they do not rebel against the
Islamic society or religion.
[1] The majority of Muslim scholars hold to the traditional view that apostasy is punishable by
death or imprisonment until repentance, at least for adult men of sound mind.
[2][3][4] Several contemporary Muslim scholars, including influential Islamic reformers have rejected this, arguing for religious freedom instead.
[3][5][6][7] Converts from Islam to Christianity have likewise criticized the traditional position.
[8] According to
Islamic law apostasy is identified by a list of actions such as conversion to another religion, denying the existence of
God, rejecting the
prophets, mocking God or the prophets, idol worship, rejecting the
sharia,
HADITHS:
Bukhari (52:260) - "...The Prophet said, 'If somebody (a Muslim) discards his religion, kill him.' "
Bukhari (83:37) - "Allah's Apostle never killed anyone except in one of the following three situations: (1) A person who killed somebody unjustly, was killed (in Qisas,) (2) a married person who committed illegal sexual intercourse and (3) a man who fought against Allah and His Apostle and deserted Islam and became an apostate."
Bukhari (84:57) - "[In the words of] Allah's Apostle, 'Whoever changed his Islamic religion, then kill him.'"
Bukhari (89:271) - A man who embraces Islam, then reverts to Judaism is to be killed according to "the verdict of Allah and his apostle."
Bukhari (84:58) - "There was a fettered man beside Abu Muisa. Mu'adh asked, 'Who is this (man)?' Abu Muisa said, 'He was a Jew and became a Muslim and then reverted back to Judaism.' Then Abu Muisa requested Mu'adh to sit down but Mu'adh said, 'I will not sit down till he has been killed. This is the judgment of Allah and His Apostle (for such cases) and repeated it thrice.' Then Abu Musa ordered that the man be killed, and he was killed. Abu Musa added, 'Then we discussed the night prayers'"
Bukhari (84:64-65) - "Allah's Apostle: 'During the last days there will appear some young foolish people who will say the best words but their faith will not go beyond their throats (i.e. they will have no faith) and will go out from (leave) their religion as an arrow goes out of the game. So, wherever you find them, kill them, for whoever kills them shall have reward on the Day of Resurrection.'"