I can't give you a reference but I am pretty sure I remember Bush saying something along the lines of how he had to take into consideration what "god" wanted when he made decisions.
As does any other religious person when it comes to matters of importance. Of course elected officials are going to have some sort of religious affiliation. That's to be expected.
He did not, however, issue executive orders with the pretext of "I, the President of the United States and loyal servant of God...". He nor any other sitting member of public office wears papal vestments.
There is a difference between being religious and making decisions based completely on religion.