It's interesting, I agree, (also this point has been addressed) Perhaps that is the reason, and if so, fair enough that would explain my issue, but, that being said the term "God" in this context means a deity, a deity of a monotheistic religion (as per the way it is written) That narrows it down, the fact that it is "God" and not allah, removes Islam from the equation. And leaves very few major religions, compile that with the fact that America is a christian nation at heart, and it was when it was founded, I would argue that the term "God" in this case does specifically mean that the nation is trusting a monotheistic, and christian "God" which is what I find problematic.
If however it was intended as a secular concept of God then the state should not be a proponent of an existent god, because whether this term is specifically christian or not, it is not abstract, it is specifically the singular term god and nothing else. Therefore it is the term for a monotheistic religion that refers to it's deity as "God" it also doesn't say in a God we trust, but rather it implies the One God, not the concept, the being. This is where I take issue. The Term "In God We Trust" being Americas motto, does specifically mean they are supporting (one) Monotheistic religion, which I would argue is Christianity, and surely the whole "church != state" thing should prohibit this.