Many philosophers have attempted to prove the existence of God throughout history - none has suceeded.
Personally, I don't believe it is possible to prove the existance of God in any objectively valid way. An American philosopher named Fritjof Capra once stated a theory in which he illustrated the difference between objective, relative truth(scientific truths, not fully verifyable but enough for most purposes), which can be communicated to others via. language, and subjective, absolute truths(religious revelations, higher insight, "Nirvana"), which are much more profound but cannot be communicated to others.
Any "proof" of God's existance might well be verifyable to the one experiencing the religious revelation, but s/he would be unable to communicate this truth to others, as they would have to have a similar experience in order to gain the same insight.
These religious experiences might be signs of a God trying to contact people, but it could just as well be a trick of the subconscious mind. So even if a person is firmly convinced that s/he has seen/heard/experienced God, s/he cannot expect others to share this insight, and other people might be just as inclined to believe that the person is insane or mentally unbalanced(and they might be right).
Therefore I do not completely discard the idea of a higher being, as I recognize that many people have experienced what they believe to be the presence of a God. However, I also believe that since such experiences are essentially incommunicable and unverifiable they will only ever have significance on a subjective basis for the person experiencing them, and s/he cannot reasonably expect others to follow the moral guidelines that s/he believes God wishes him or herself to follow. That's one of the reason I find the idea of organized religion a bit silly. To me religion can never extend beyond the essential subjectiveness involved in its perception. I'm not religious now, as I have not seen or experienced anything which would lead me to believe. Even if I did believe, I would not expect others to follow me.
I don't think the fact that there are certain holes in human knowledge can serve as proof of the existence of a god. Many of the unexplicable phenomena which earlier lead to the belief in divine beings(thunder, the change of seasons, etc...) have been explained scientifically later in our history. I see no reason why that should essentially be any different about current holes in our knowledge.
Besides, the act of introducing a God to explain such phenomena will often cause more problems that it solves: "The Universe exists = God created the universe" is a classic argument, but what does it really change? What about the existance of God? And if God can have existed forever, why not the universe in the first place? The only escape a theist can use here is the good old "The full concept of God is incomprehensible to human understanding". But if that is so, how can mere humans tell what God does or does not want us to do? Then we hit the wall of subjective truth again.