Is there a threshold for belief in God that you think is necessary for a healthy society? 50%? 75%?
It's not true at all to state that morality has no grounding without a "higher power". (See also: https://en.wikipedia.org/wiki/Ethics)
For example: belief in a higher power simply isn't required to allow people to make their own medical decisions. Belief in a higher power isn't required to give someone food.
It's absolutely fine to propose religion as an ethical framework, but I don't think it can possibly make sense to propose it as the only ethical framework, or to propose that society will become worse if humans "move away from God".
There are plenty of good alternatives.