"G-d"

Many religious Jews will spell the English word "God" with a dash in it - "G-d." I believe that this has developed from the use of replacement names (כינויים)for the divine name in Hebrew, for example using the Hebrew for "Lord" (Adonai) instead of YHWH. Even "Adonai" has now become too sacred to say in ordinary (non-prayer) speech, so people will now replace it with "Ha-shem" ("The Name").

This is something I used to do, when I was an undergraduate, but stopped doing - but I still will not write out the divine name in Hebrew (I'll use the English transcription instead), and in classes I generally don't use the modern scholarly reconstruction of the pronunciation, "Yahweh," unless when I'm talking about the Documentary Hypothesis in my Hebrew Scriptures class.

Many of my Jewish students will write "G-d" or even "Ha-shem" in their papers, which doesn't surprise me, but I noticed a few years ago that some of my Christian students also wrote "G-d." I've asked them in the past why they write the name that way and have gotten various answers. I've now just encountered the same usage on the internet, in an article about an entirely different topic - Reihan Salam's column on Facebook etiquette on Slate.com.

A Christian wrote to him objecting to his flippant invocation of Allah:

I find the example you used to show how to reject friend requests just felt wrong. I'm a Christian, not Muslim—but I never would speak so flippantly about one of G-ds commands. I do respect that Christians are told not to be friends with "the world," and Muslim faith I think commands the same, but "sorry, man Allah commands it" seems like you're using G-d as an 'excuse' ... would you really want someone to say something like that if they weren't Muslim? Wouldn't that show enormous disrespect for your G-d? Not to mention should a Muslim say it! Please, can you consider this? Thank you.

Reihan Salam doesn't comment on the writer's use of "G-d" but it really struck me. I am wondering how common this is among Christians, and what rationale people have heard for writing this way? Is it something they picked up from Jewish friends? Is this something that pastors or priests are now teaching their parishioners? And if so, what is their rationale?

Any answers from my readers would be welcome - I'm also curious to know if other professors have noticed the same thing in student papers.