You know the expression; someone says it to intensify a preceding statement of personal intent or resolve, as in, “I’ll figure this out, so help me.” It doesn’t matter if the person being addressed is the intended victim, as in, “Smurdley, if you screw up the Johnson deal I’ll have your head on a platter so help me”. Who is being asked for help? The intended victim? The general public, or anyone who happens to be around?
A friend once suggested, rather preposterously, that So was an Egyption god that was being invoked by the expression, but I don’t think that’s the case.
Invoking God’s name when not in prayer is prohibited by the Third Commandment. Thus, many Christians leave out “God” when using the phrase for trivial matters.
This has become common practice within the English language regardless of the faith (or lack thereof) of the speaker.
Bzzzt! Ancient Joke Warning! Bzzzt!
.
/
/
/
/
/
/
/
/
/
/
/
A guy at work tells his co-worker, “Sadie, if you bend over one more time in that short skirt, so help me, I’ll rape you!”
Sadie looks at him over the top of her glasses and purrs, “So rape me, I’ll help you.”
It’s originally an oath–“I will do such-and-so, so help me god.” So is used here in its meaning of “in that manner or to that end”; what they’re really saying is “Help me keep my promise, big guy.”