There are many believers that God does not exist: the atheist.
But one thing this agnostic does know for a certainty:
The Concept of God exists.And that irritates all the rulers and demigods and their nefarious aides that ever existed.
Whether or not God exists, the Concept of God stands between the individual and those who would treat him as less than human. All the anti-theistic efforts in the world can never put an end to the Concept.
Where there are human beings -- or, indeed, any thinking beings -- there will be the Concept of God.