It's a nice motto. The founding father's would probably have preferred "In Our Creator, Country, and People We Do Trust" if anything along those lines were to be elected as the motto. But "God" is a blanket term, honestly. Though the intention is obviously "Christian" (Although the altruistic nature of this proposal could be questioned, all considering), the idea of Faith has always been a major part of American culture, so it is appropriate. The government isn't endorsing a church, it isn't becoming a theocracy, it isn't forcing anyone to believe anything. If you don't like the motto, do something about it. Have it changed. But honestly, it doesn't divide anyone at all. If your bothered by the word "God" being uttered by the government, then you may have more pressing issues to deal with than the nation's motto. It isn't unconstitutional and it certainly isn't anything surprising - American history is filled with religion and spirituality just as is the history of the entire world.
Personally, though, I think it would be more appropriate if on every dollar bill we printed there be a little note "Spend by next Thursday" with the motto "Trust Me....Please." on top.