The most common and basic definition of a God is something that operates outside the natural order. Simply, a God cannot be naturalised regardless of the resources and capabilities that could ever be done. In short, God is the supernatural that can never be proven or shown to exist, it is unfalsible, which means it doesn’t exist. [You cannot prove that something doesn't exist, only that something does exist.]
This theoretically means that anything and everything that does exist can be shown or proven to exist. As God by its very nature of its definition operates only supernaturally, it can never be brought into existence.
This is the path that simply claims that anything that is there can be shown or proven to be there regardless of our own current limitations proposing we can some-day show it. This doesn’t claim everything that is currently classified as supernatural is actually supernatural; it claims that anything supernatural which can never be natural does not exist. As a God operates in the supernatural, therefore not natural, anything which is natural cannot be a God.
This theory does not deny the possibility of Massively Powerful Beings (MPB). A MPB is simply a being or even a technological object of immense power which can currently shock and awe us with our current levels of understanding. In short, it would be going back to 1000 BC with a Helicopter; it would shock and awe the people of that time period through their lack of understanding. In this, it could allow for the possibility of (in pure example) an Artificial Intelligence UFO at the Centre of the Universe controlling everything at a quantum level. The theory would only state that such an MPB is part of the natural world, not the supernatural; therefore, an MPB is not a God (by definition of a supernatural being). For instance, an argument could be that an MPB created the Big Bang, because of its existence and part of the natural world and from greater understanding; this MPB is not supernatural and therefore cannot be a God.
This theory also disagrees with any labelling of anything as a God. While other theist arguments might be the personification of let’s say energy being God. They say that energy creates matter, and is the fundamental source of everything in the Universe, however, as energy is not supernatural, it is not a God by the definition.
Bookmarks