In a philosophy class at college I learned that one old Christian, Saint Augustine, said there are five proofs for God's existence. 1.motion-every movement is caused by a previous movement, nothing moves on it's own. 2.cause-every effect has a cause, the universe must have a cause. 3.contingency-there must some source of life that sustains life, that would have to be above life itself. 4.perfection-the universe is too perfect for it be an accident, atoms didn't just randomly collide to make planets, stars, comets etc. 5.order-only an intelligent being could make such a harmonious universe as ours, we can see a pattern of creation: light and darkness, kinds of animals, male and female, seasons that correspond to each other etc. etc. Of course this was all by an old guy who wore robes and wrote with a feather and ink. I think real Christians would say the proof is faith, the scriptures say "we walk by faith, not by sight." 2nd Corinthians 5:7 NKJV. I believe it was Immanuel Kant, a drop out from Lutheranism, who believed in inherent knowledge, knowledge "apriori" or before experience. Kant thought we could infer a lot about the "noumenal" acausal world from the "phenomenal" causal(caused) world, but that the world wasn't just our experiences and there was something like "gnosis" that could be found within the self. Or maybe that's just my take on it. I think David Hume is the father of my own school, agnosticism. I think Rene Descartes said something similar, that is that all we see could be an illusion created by a magician or demon and we can't be sure if anything really exists except ourselves. Again that's just my take on it. And I felt like I needed to respond, it is my area of knowledge. I did fail philosophy, but I got a lot of good books on it.