An oponent once aproached an hassidic man and told him, "The difference between us and you is that we think about G-d all day and you think about yourselves all day!" The hassid retorted, "Yes, of course. That is because you are certain that you exist and spend all day wondering if G-d exists. We are certain that G-d exists and spend all day wondering if we exist."
The Rambler once had a friend named Yoni, who heard that story and realized that, indeed, he had no proof that he existed. The Rambler would endeavor to convince him that his existance was an undeniable fact, but no arguments could be found to be sufficiently convincing. Can
you prove that Yoni exists? You have probably never seen him, or even heard of him before now. He may just be a figment of the Rambler's overactive imagination. Proving the existance of G-d is a much easier feat, however. He is everywhere. You can't look without seeing Him. He is the one experience that everyone shares. In the words of the Chief Rabbi of Suburban Guadalajara:
Think simple: You wake up in the morning and, even before coffee, there is. Reality. Existence. Not "the things that exist" but existence itself. The flow. The infinite flow of light and energy. Of being, of existence. Of is. Think of all that flow of isingness all in a single, perfectly simple point. Get into it, commune with it, speak to it, become one with it --that is G-d.
