I think the idea is that the phrase "God" is generic and not related to any religion specifically, thus not a state endorsement of any religion. It can even just be a symbolic interpretation of some abstract concept.

It's empty rhetoric that makes religionists feel comfortable without seeming all that threatening to nontheists, so I suppose it's kind of a compromise.

__________________
"It's never over... BOY!"
The Tall Man, Phantasm III