The scholars have mentioned that a person may become apostate for many reasons which can nullify his faith. These reasons would make someone's blood permissible to spill [to be killed for apostasy] and his wealth permissible to be usurped, because he is no longer a Muslim.

"Correct Beliefs and What Opposes Them" - a pamphlet published by the Saudi Ministry for Islamic Affairs and donated in large numbers to British mosques by King Fahd for free distribution.