A person who abuses or refers to holy scripts and/or god(s) to promote unholy cause by finding texts in the scripts to justify aggression, abuse of power, and unwillingness to listen to reason or other opinions.
Also persons who profess that a god (Allah, Yahwe etc) has told them that they are on a mission sent by that god.
World's #1 godfucker: G.W.Bush
The world's best known godfuckers are GWB, Osama bin Laden, Jerry Falwell, Ann CDoultre.
Most evangelical Christians and neo-cons are godfuckers.