This fic might have been on fanfiction.net, I'm not sure. Basically, fem!Castiel is God, and everyone( as in normal citizens) found out about it. There was one scene where she was with priests (maybe at the Vatican?) and they asked to stop appearing as a female and kept calling her 'Father' and maybe Queen Elizabeth II appeared somewhere in there too. And it's Dean/Cas although I don't remember if it's established or pre. Thanks in advance!! :D