God is essentially a contradiction of human knowledge and understanding. Humans, in order to evolve as sentient beings, have been forced to limit themselves and their surroundings to an area of understanding; quite nearly as much as a dog would define its leash or food bowl as positive items of interest. To give rise to God as an almighty and unlimited being is to venture into a land of conjuration and cognitive betrayal.
To validate the existence of God, one must come to a firm, objective, and unwavering conclusion about what God is and what God is not. God must be a definite being; that is - God must have an objective definition that can be positively assessed by human beings of all religious, ethnic, and linguistic backgrounds. Here a conflict is risen: to be defined is to be limited to certain parameters, but for God to be God (i.e. perfect in every conceivable context), God cannot be imposed with any limitations.
To fit into the current understanding of the model of existence, God must be confined to a time and a place. God must also have a finite amount of ability. God cannot be attributed omniscience, omnipotence, omnibenevolence, or any of the other divinely superlative adjectives, because these words imply that God is unimpeded in some fashion. Our language, by its nature, is built to define and contain objects and ideas. God, in order to exist, would have to transcend every possible definition imposed by humanity. If, by some circumstance, God does exist outside of linguistic definitions, then God is not any of the many thousand deities that have been worshiped throughout civilization. God, in that instance, is a phantom being whose existence has arisen by a mere coincidence.
The problem of the existence of God is deepened by comparing and contrasting God with the natural world. God is said to have unlimited power; natural law is consistent and immutable. Either God has full, unflinching authority over the laws of physics at all times, or God does not. The actualization of a single miracle would depose all of the scientific and rational work done by human beings in the last 3,000 years. There is here an inherent conflict between science and faith. One lives through observation and exhaustive revision, and the other survives through the geneological indoctrination that one area of life exists that should never be contaminated by inquiry and doubt. Either God is God, nature is nature, or both of them are artificial constructions.
There is no proper definition of God that substantiates in any way with even the lightest consideration of the world as humans have come to understand it. God is a conceptual gas, escaping any absolute definition; and thus, to every reasonable extent, God escapes the bounds of reality. God has no land and no subjects over which to prevail, except in the incoherent realm of fiction. God is in every way a contradiction. And, as long as contradictions are not permitted the tablet of truth, God will forever dwell among the idols of fantasy.