There are so many phrases in our common language that involve God in them. The most common is probably the "God bless you" so often quoted after a person violently expires air from the nose and mouth. But there are other ones like before a great voyage or adventure people will say "Godspeed!" to the voyagers.
These phrases are very common. Oh my God, Goddamn, thank God, only God knows, God-awful, godforsaken, godsend, God's gift, God forbid, act of God. This is hardly an exhaustive list but they are what come to mind.
Anyway, I mention them to discuss the issue of how many atheists find such phrases somewhat offensive and refuse to use them. I have to admit that at first I had that reaction myself, but what's the real harm in simply using the word God? Those phrases don't actually mean anything about God, but mean other things altogether. When people say "thank God," they aren't actually thanking God, they are saying that they feel relieved. When they say "God forbid" they aren't actually invoking God to not allow something, they are expressing their distaste for some suggestion.
We have idioms like this of all sorts that are used and wherein the literal meaning is not believed in by the people who use them. When a person wakes up on the wrong side of the bed are you suggesting that malevolent spirits which dwell on the left side of the bed bothering the person? Does crossing your fingers mean that you think making the sign of the cross will protect you? When you are giving the third degree are you giving credence to the medieval natural philosophy involving the four elementary quality of bodies? When one kills in cold blood, are they acknowledging the validity of a relic of medical theory where excitement was thought to actually heat the blood. When you're unsure and in limbo, do you see yourself as literally being in purgatory?
Given all these examples, why then do atheists get so bent out of shape with the idioms regarding God? Sure, the literal object of the idiom may currently be taken seriously by some people, but that's no reason to care or be offended by their usage. The word God is not offensive, nor is the idea of a superior being even a threat to skepticism, nor does saying them imply any belief in the literal meaning of the phrase. So for God's sake, stop being so sensitive.