From the temporal perspective, the existence of God is unknowable, yet undeniable. As for His nature, He is infinite, and it is quite beyond my finite mind, to fully comprehend Him--though there is no harm in trying.

John, I might point out, that there is much that simply can't be known. How did the universe begin? Who could know? Not that science is unable to take some clues and construct a scenario with them. However, at this point, I could reverse roles with you and apply my skepticism to what you must simply take as an article of faith. That is, the universe owes its existence to some material cause and reality is reducible some mathematical equation, or the like.

I suppose the bottom line is, that we are all guilty of conforming reality to what we think or want, it to be. In my instance, this is translated into trying to conform God into what I think He should be. Though, I am wholly resigned to His existence, as nothing else makes any sense to me. Indeed, I would say, that if He doesn't exist, there is no sense to be made of it.

You ask me how I know that God exists. One doesn't know God in the temporal sense. He is known in the heart and by His Spirit. As a believer, I have learned to look through the material to see the hand of God at work in my own life, and in the lives of others.

I first came to know Him, at the end of my own reluctant journey to that place of death, the foot of the Cross, where I died to the world. Yet it was there, that I learned what it means to live, and to be free.

John, I get the idea that you endeavor to reason me out of my faith [though I am quite sure it is unreasonable], or what I believe. I am OK with this. However, I must say that you can no more talk me out salvation, than I can talk you into it. And there is a lesson for you there, my friend.