I take the Ontological argument's definition of God - "God is that of which nothing greater can be conceived" as my 'belief' in God. An all-powerful celestial being would be so distant, so great, so beyond our simple human existences and the rules we follow that there is simply no point in trying to worship or make contact with it. It is so far beyond us that even the concept of 'existence' comes into question.
And therefore there is no point in trying to show some sort of recognition in something so transcendent, because it really does not care for us.
If by some means the gods and spirits of our religions were to proven to exist - we might call them "God" or whatever, but the way they are described shows that they are fallible, restricted beings when in comparison to a true, all-mighty God. They are frauds in comparison, no matter what power they have over us. They take human or physical form to contact us - that makes them limited, and therefore not the greatest.
And were these celestial beings to come into existence and start laying down their supposed religious laws - they would still be evil, twisted, cruel things. As a human being, I could only oppose them. And the religious groups that stem from such religions have done so many horrible things in the world, and are so out of place in modern society, that I have a huge dislike towards them.
My spiritual beliefs are agnostic, my religious beliefs anti-theistic. Those are mine, of course, I will never try to influence anyone else to my point of view.