Let me illustrate this point with using this graphic.

Christians, Jews, and Muslims believe in one God. (There is one hand holding the Universe up)

Atheist and Theravada Buddhist believe in no God (No hand holding the Universe up)

Polytheist and Mahayana Buddhist believe in many gods (Many hands holding the Universe up)

Now can God be one, many, and none all at the same time?

Obviously not.