"Prohibited to you (For marriage) are:- Your mothers, daughters, sisters; father's sisters, Mother's sisters; brother's daughters, sister's daughters; foster-mothers (Who gave you suck), foster-sisters; your wives' mothers; your step-daughters under your guardianship, born of your wives to whom ye have gone in,- no prohibition if ye have not gone in;- (Those who have been) wives of your sons proceeding from your loins; and two sisters in wedlock at one and the same time, except for what is past; for Allah is Oft-forgiving, Most Merciful;" - Quran 4:23 (read more)

"Narrated Anas bin Malik: Allah's Apostle said, "You should listen to and obey, your ruler even if he was an Ethiopian (black) slave whose head looks like a raisin." - Sahih Bukhari 9:89:256 (read more)

"...[If] your friend became an atheist and did not believe in Islam, and he died in that state, as appears to be the case, then it is not permissible for the one who knew his situation to offer the funeral prayer for him or to say du’aa’ for him, or to wash him or shroud him or bury him in the Muslim graveyard..." - Islam Q&A