On my mind

I am extremely bothered by Christians who say omg or write it. It is blaspheme. Why do they do it? I have a friend from grade school who does not profess to be a christian but she says that almost every other sentence. It bothers me a great deal.
Also by- words. It seems like everyone uses by- words. WHY? Can you not express yourself without saying a by- word? Look those words up on the Internet. See what they mean. If you are going to say a by- word it is exactly the same as saying the actual curse word. Why bother trying to tone it down? Or are you trying to tone it down? Are you just cursing in a way you can get a way with?
I have a niece who is leaving in two weeks for mission work. Tonight on her face book status she said leaving in two weeks omg omg. A missionary saying oh my god oh my god? What?

The free dictionary on line defines it thus:
by·word also by-word
play_w2("B0593500")
(bwûrd)
n.
1.
a. A proverbial expression; a proverb.
b. An often-used word or phrase.
2. One that represents a type, class, or quality: "Polyester got its déclassé reputation in the 1970s after cheap, poorly made double-knit leisure suits became a byword for bad taste" (Fortune).
3. An object of notoriety or interest: The eccentric poet was a byword in literary circles.
4. An epithet.
Look at #4. That is what a by-word is.
An epithet is:
ep·i·thet (p-tht) KEY NOUN:
A term used to characterize a person or thing, such as rosy-fingered in rosy-fingered dawn or the Great in Catherine the Great.
A term used as a descriptive substitute for the name or title of a person, such as The Great Emancipator for Abraham Lincoln.
An abusive or contemptuous word or phrase.
Biology A word in the scientific name of an animal or plant following the name of the genus and denoting a species, variety, or other division of the genus, as sativa in Lactuca sativa.