You can't be Free and "Under God" at the same time. "Under God" invariably requires a group deciding and enforcing what is "Godly" and therefore approved and what is "Ungodly" and therefore punished.
Everyone has a different idea about "God" which creates an infinite set of "unbreakable" rules foisted upon The People, resulting in a prison based society where everyone is a criminal just waiting to be caught, enslaved and imprisoned. Perfection being the enemy of good, means that evil is the result of trying to be perfect in "God's eyes".
Freedom is enough without a Big Brother gov't watching and waiting for the inevitable error of humanity. Your relationship with "God" is personal…so you don't need to bring other people into it.