What is the origin and real meaning of God damn?

[QuestionR]

What is the origin of the phrase? And just what is the speaker saying? I contend it is requesting God to damn something/someone as in the opposite of "God bless you". So many folks take offense when someone utters "God damn (hurrricanes)" thinking it is taking the Lord's name in vain. But if one is requesting God's intervention in smiting an evil, how can that be considered wrong? If so, then it would be equally wrong to ask Him to bless something...

[pega]

I think this saying was quoted in shakespear plays and also you could look into Joan of Arc as remember it in some films plays

in what your asking I would say that if something is wrong then its anger towards who has done wrong don't hear so much "God" in it  people just say damm it or damm them .

[Kingaroo]

I think that "to take the Lord's name in vain" means to call down God's mighty wrath to suit your own purposes (vanity).  Having God damn the hammer that you smacked your finger with would be "in vain."

I'd like to know for sure though if my assumption about vanity/in vain is correct.  Most of the time when we say something was "in vain" we mean the task was attempted but the effort was unsuccessful.  There's no point in telling people not to "take the lord's name unsuccessfully."