It is the rage with people today to say" O God" or "O my God" all the time. But remember, with Gods name comes the full weight of His person and nature. It is wrong to use His name in a casual exclamatory way because it is wrong to treat God in a casual way.
Being good Christian folk we wouldnt do this directly of course, so we have come up with other ways of doing the same thing. We do this by using euphemisms for Gods name in casual exclamatory ways.
A euphemism is a nice or seemingly more polite or tasteful way of saying something. Using a euphemism is often a way of pretending we arent saying the thing we really are saying.
So instead of saying Gods or Jesus name, we say things like:
Ga
Golly
Gosh
Gad
Ee-gad
God awful
Gee
Gee-whiz
O Lord
Oh heaven
Heaven forbid
Good Lord
Lordy
Now I know you are going to be calling me petty, or maybe a legalist here. But I ask you to think about the words that come forth from your lips. Do they build up the name and reputation of God? Since God isnt trivial, His name isnt trivial, and it shouldnt be used in a trivial manner.
What if your child or spouse or friend was using your name this way? Everytime they did something dumb or heard something unbelievable they said your name.
These common exclamatory expressions are empty expressions using Gods name. The Third Commandment says that we arent to lift up His name in emptiness, which is what saying these things does. When found upon our lips these expressions do not please the one whose name we are called to honor.