What makes you think you need a phrase?
Having a phrase that excludes all "non-God" people seems counter to all the principles of inclusiveness of minorities one would expect of America.
It's more like a phrase you expect on the currency of the Vatican, or Iran, than that of a union of democratic states.
But if you have to, how about going back to old one?
Quote:
In 1956, the Cold War was in full swing, and the anti-Communist suspicion of the McCarthy era was at its height. Partly in reaction to Communism (which was commonly associated with atheism despite being merely devoid of an official religion), the 84th Congress passed a joint resolution to replace the existing motto with "In God we Trust." According to United States Code, Title 36, Section 302, the new motto officially displaced the original 180 year-old national motto "E Pluribus Unum" (Out of Many, One)
Wiki.
To me, that says..."United"...."States".