OK, maybe this may be a little philosophical, but I’m going to try to answer your question…
First of all, we have to define God. Thousands of definitions exist, but I’ll just say that for there to be a God, he must be some kind of all-powerful and all-knowing being. Otherwise, whatever we want to call God, if these qualities do not exist in his essence, then he is something other than God. So with this working definition for God, let’s see if he can exist or not.
If this being exists, insofar as he is all-knowing, then there is nothing which we could discover that he would not already know. If I could, by reason, come to some absolutely certain method for proving his existence, he would first know that method before me. Therefore, I can never outwit God, otherwise this being we are talking about would not be God and must be something else.
Second, in virtue of God’s all-powerful quality, I can never out-maneuver him. He would know my actions before I would (the all-knowing quality) and would be capable (the all-powerful quality) to, if he so chooses, keep me from ever discovering him. Therefore, God can only be known by his revealing himself to man. To say he doesn’t exist or that he does is a task that could, if an all-powerful and all-knowing being existed, be thwarted by that being with his own enacting of laws of science, limiting the capacity of the human mind, dodging man in man’s pursuit of him, etc.
My point is that God can only be known when he chooses to make himself known. This is consistent with my definition of God; should we change the definition, then this argument is useless, I suppose.
I have felt that he has revealed himself to me, and that will be the task of my life to better comprehend his essence and power; but this is, I recognize, subjective evidence for the existence of God. He can only be known when he chooses to make himself known, and for that I hope you continue to seek.