Much like oh my god, or the shortened form omg, oh my gosh can also be condensed into omg, and thus people will have no idea whether you are talking about god or gosh. However, angry Christians who hate to use the Lord's name in vain, usually type oh my gosh online, rather than oh my god.
<illiterate girl> omg u no dat movei wiff ashtin kosher???
<jew> i like kosher food.
<christian> do you dare say the lord's name in vain!?!?!?!?
<illiterate girl> no omg sry plz
<athiest> maybe she said oh my gosh.
<christian> b-b-but it may have been the other one...
<athiest> oh my god, you mean?
<christian> YOU ARE GOING TO HELL!!!
<athiest> I don't believe in Hell.
<christian> ....
<illiterate girl> omgz u loserz lolz
An exclamation of surprise, excitement, sadness, or fear. Pretty much the wimpy way of saying "oh my god." usually used by strong christians or when in a group of christians and you just want to be safe and not offend anyone.
Sadness:
Person 1: I just saw a dead deer on the side of the road!
Person 2: Oh my gosh, that's so sad!
this word was being said less and less in the hallways of Hanover High until a young "girl" by the name of Carmen A decided that she'd say before and/or after every single sentence. usually it is said in a gay, i'm a 12 year old girl on helium voice which drives me and drew into random fits of craziness because we cannot take her madness anymore
oh my gosh guys!! i got last in my track meet yesterday because i was running so slow because nick wanted me to get rugburns on my knees and oh my gosh guys i didn't even know what that meant oh my gosh guys i'm hungry!!