The bible defines religion in James 1:27:
"Pure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted from the world."
That word "world" is translated from the word "kosmos" which simply means "an apt and harmonious arrangement or constitution, order, government."
So the official religion of a US Citizen is the impure type and is called the US Government because that's how society has chosen to help the needy. State corporations commonly called churches long ago gave up that responsibility. For example, how many of their members are collecting social security benefits paid for by their children? And how many churches define helping the poor as helping them get signed-up for state welfare programs?)
So both the so-called athiests and churchians worship the same elohim (rulers/judges) and serving the same father.