Thanks vs. Thank you

[Tortoise]

A friend of mine says that "thanks" is a short form of "thank you". And instead of saying "Thank God", he'd say "Thanks God"

I don't totally agree with him, because I've learned that "thanks" is a noun, so the terms "thanks God" is grammatically wrong. I think "thanks" can be replaced "thank you" in most of the cases (and vice versa) but they are different, I mean "thanks" is not a short form of "thank you".

So, who is right?

By the way, "Thanks in advance" or "Thank in advance"? ... Well, I think "Thanks in advance" is right

Tortoise.

[Yankee]

Hi Tortoise

You are absolutely right.