Proof for God's existence is something which many different groups, both believers and non-believers alike have attempted to bring into light, whether to prove or disprove depending on their position on the subject. Science in it's deep rooted nature of empirical evidence is usually dismissive of God's existence; or in some rare cases is used as proof, though this proof can never truly be demonstrated given the empirical and materialistic approach of Science. By God's very nature, proof of it's existence through Science, which has not yet occurred, seems a fallacy. In order to truly understand the nature of God or the concept behind God it would perhaps be best to take a philosophical approach. Philosophy's basis is one of understanding, as opposed to finely analyzed physical evidence, and thus is a better way of reasoning on the position of the God questions.
Being that God's existence is unmeasurable by Scientific standards only the dialectical approach of Philosophy can be used to past judgement, at least to a demonstrateable point. While Science is designed to ask "how come" Philosophy says "why so", the whys are what should be emphasized regarding the nature of God. Philosophy in its vast span and long existence on Earth, even predating modern Science has developed a number of thinkers and schools with their own answers to the God subject. There is of course the wager position, which can be summed up by Immanuel Kant who stated
"act in such a way that the maxim of your will could always hold at the same time as a principle of a universal legislation." This of course parralels with Pascal's Wager which states that it is better to believe in a God and be incorrect than disbelieve and be incorrect. The nature of God was and can also be analyzed by Philosophy in a detractory form, an example being Epicurus's critique of God and the nature of evil which was later cleaned up by David Hume into the well known riddle. Being that much of what is known of God is based off of word of mouth and written works, only the former form Philosophic analytical thinking can truly expand upon the God concept, despite how hard some may attempt to use Scientific reasoning to prove God's existence, no unrefutable theories for this being the case have ever been produced from the Scientific community. There can also be a possibility of demonstrateable proof of God's existence in Philosophy through Telelogical Reasoning for example. Intelligent Design is a modern day attempt to adapt to Scientific critique of the God question which is permeated by Philosophical parameters.
Philosophy having played a role in the development of nearly every code of action and institution on the planet, is perhaps the best tool to be considered when contemplating the nature of God. Given the esoteric nature of religion Philosophy is better prepared to deal with theological questioning than religion which usually works outside the realm of the undemonstrateable. Philosophy's flexible nature allows it the reign needed to study the God concept from every viewpoint, whether one sees theological phenomena as natural or supernatural, occuring or void.