Why does pushing God out of your thinking lead to an immoral lifestyle?

Les explains that once people push God out of their thinking, they begin to worship anything and everything but the one true God, and as a result they open themselves up to the immoral lifestyle. He supports this with a secular university writer who said a society cannot last unless it is guided and controlled by religious values. Even a religion one might disagree with still provides guidelines that keep people within a certain spectrum of behavior, which is necessary for society. Without restraint, anarchy comes, and no nation can endure. Rome is a prime example: despite its great military machine, it became politically, economically, and morally corrupt and defeated itself. Historians warn America is going down the same road and will destroy itself from within, not by an outside power.