I am a pixieist, what do you think of my proof that universe creating pixies exist?

[Tonus]

At the end of the day this argument is simply a joke, to mock the existence of God and keep in mind the atheist does not even believe in the universe creating pixies even though he uses the argument against the existence of God.

The atheist uses the argument to show that anything can be substituted for "God" and be defended in exactly the same way, thus invalidating the method. If a particular argument relies on a presupposition that must be accepted before any other work can begin, even though it cannot be proven on its own, then it's open to the sort of abuse you see in the OP. If you think that using "pixies" is too overt to be taken seriously, just use "Allah" instead. Surely you must be aware that we have had many Muslims explain to us that it is their version of God that is true using almost identical arguments to yours? Why is your "step one" valid, and not theirs?

If the atheist is just rejecting God and all of these strong arguments and evidence for His existence, why aren't the theists of the world united in one single set of beliefs? Why is it that even people who claim to worship the same God that you do --and who would agree 100% with the first paragraph in your post-- feel that you are wrong enough that it will affect where you end up in the afterlife? Why are there tens of thousands of denominations within Christianity even though they all follow the same God and the same book? Why does your explanation only mollify such a relatively small number of people if it's such a slam-dunk? Why did humanity go through thousands --if not millions-- of Gods during a period when this incontrovertible proof and evidence should have been just as strong --if not stronger-- than it is today?

I'll give you one reason-- because people are willing to accept the kind of thinking exposed by the first post in this topic.