Positing that God exists and is perfect (by the fact that he is the moral authority and is thought of as absolute perfection according to the general consensus); a change that he makes would mean that he was less or more perfect before the change came about. This follows the logic that something that is absolutely perfect must be unchangeable, because change is either for better or for worse. Any change would mean that God was more perfect or less perfect before or after the change. This is impossible, because God is absolutely perfect, there can therfore be no change in God or his "thoughts".
This change I'm referring to is the creation of the universe. The creation of the universe means that he underwent a change, because He was previously lacking a universe which he now has, and as I have stated, change in God is impossible. Logically, then, there could have been no creation, and the logical conclusion is that because God is absolutely perfect he must not have created the universe, or anything for that matter. Nothing therefore exists. We are all a delusion.
Though for a being (us humans) to think about his own existence precipitates that we be in existence. Therfore God should not exist by the very fact that we can question our existence. For, our existence is impossible if we believe in a perfect God (following my previous reasoning).
In summary, does our existence, which is a creation and therefore represents some manifestation of change, imply that God is not perfect or simply does not exist, because perfection precludes change?