What is the ruling on a Muslim who changes his religion?

Apostasy is disbelief after Islam, and it is the only sin among all misdeeds that nullifies all good deeds if the one who committed it dies upon it. If the apostate returns to Islam, the reward for his deeds is restored, and he is not required to make up for the acts of worship he missed.

The deeds of an apostate are nullified if he dies upon his apostasy, by scholarly consensus, based on the Almighty's saying: ﴿And whoever of you reverts from his religion and dies while he is a disbeliever - for those, their deeds have become worthless in this world and the Hereafter﴾ and ﴿And if they had associated others with Allah, then [all] that they used to do would have become worthless for them﴾.

If the apostate does not return to Islam, he must be killed, based on the Prophet's (peace and blessings be upon him) saying: "The blood of a Muslim who bears witness that there is no god but Allah and that I am His Messenger is not lawful except in one of three cases: a life for a life, a married person who commits adultery, and one who abandons his religion and separates from the community." And "Whoever changes his religion, kill him."

If the apostate is killed, he dies as a disbeliever, so he is not washed, nor shrouded, nor prayed over, nor buried in Muslim cemeteries, and he will be among the people of the Fire. The earth once rejected the body of an apostate during the time of the Prophet (peace and blessings be upon him).