[dyed_in_the_wool]

For some, taking the Lord's name in vain and cursing are equivalently 'bad things'.
I would determine the context first.
This person may be trying to install some moral sensibility that could be valuable.
Temperance should be your watchword.

[mountaineer]

Sage advice. There's a big difference using "God" as a curse word vs. "God bless you."

[shattered]

I totally agree and it sounds as if that is the teacher's intention.

[azhenfud]

I had thought the same since there are many that use "god" as an exclamation of vanity instead as a reference to the Sovereign. Context is everything and to restrict the use of the former for establishing reverence for the latter may be a plausible intent. Just my opinion, but best one not use "God" at all if not used in proper reference....