I'm trying to curb my profanity but when I get really stressed I get quite vocal. Not to be confused with being very angry in which I go silent and is very effective for those who know me.
Even after my mental transformation I still fall back on "goddammit" in order to pass the blame of my mistake.
Most of the time in stressful situations I use very gutteral language like "motherfucker" or "mutha fucking son of a bitch"
On the less extreme I use the phrase "dumbass" from the 70's show (yes I like the Red Foreman character)
and something from a funny movie called "Johnny Dangerously" I like the quote "Dem Farging Bastages" from a character who wasn't very good at the Enlgish language.
As a professional linguist, I have to disagree with the statement "one cannot understand English without a basic knowledge of Christianity". That's a rather unsupportable assertion. Sure, there is much in English with what seems to be Christian origins. It's probably more accurate to say, English as we know it would be different without the influence of Christianity. It would also be different without the influence of just about every language - ancient and modern - that has ever existed. It is also accurate to say Christianity would have no language at all without Latin, Greek, Arabic, French, etc. and the many cultures from which it has borrowed or stolen. Let's remember that Christianity didn't invent the language it uses. It also didn't invent much of its own content. Borrowing and making one's own is a long tradition far outdating Christianity.
At any rate, I believe it quite possible and common for persons to speak English with little to no reference to Christianity. Sometimes, I go months without doing so.
How many Atheists, when they have an orgasm exclaim "god!" What spoils the mood more: when you say it or when your partner says it?
I just grunt and give a bear growl as loud as I possibly can. Then afterwards I howl at the moon.
As to your changing language idea... that's a tactic for totalitarians and hucksters, and a basic part of conditioning people to the Party in 1984. You WANT to have something in common with the Party? War is Peace, Freedom is Slavery, Ignorance is Strength. Not an association in references (mild, or otherwise) that I would like to have. Words mean what they mean. It's a fight for secularists to stop the religious and totalitarians in this country to stop changing meanings, not do the same thing with a different spin. That's a dangerous road to go down. I'd seriously re-think where you want to align yourself on that front, and just leave antediluvian words such as religious exclamations and swears in the dust if you don't want to use them.