Ephesians 3:18-19. "I pray that you may have the power to comprehend with all the saints, what is the breadth and length and height and depth, and to know [i]the love of Christ that [b]surpasses knowledge[/b][/i], so that you may be filled with all the fullness of God." I think this hits the nail on the head of the fact that we cannot possibly understand God and His very existence, because it is beyond our knowledge and therefore proves that his existence cannot be proved by man, but by faith.