You have kindly let me share our correspondence with other people (at least my mother reads this blog). As a fairly new Christian (four years), you are beginning to think about your faith. This is good and a natural part of being a faithful Christian and I appreciate the chance to share my experience.
To be real faith, of the Christian kind, there should naturally create a yearning for greater understanding of our mutual commitments. Faith is not believing despite the evidence or against the evidence. The faith isn’t on trial, but our understanding must grow. Doubts are natural and wholesome: if you had none, then you are an ideologue and not a faithful Christian!
I am responding less as an analytically trained philosopher and more as a fellow Christian who has enjoyed seeking understanding of Christianity for forty-two years. If anything I say seems overly simple, remember the limits of email and a blog post and know I would always be happy to point to deeper writers and books!
You asked for my “favorite argument for the existence of God.” Like the existence of any other person, I believe in God first because I have experienced Him. Unlike human persons, my experience of God is not something you can see. God is a spirit and my experience is an inner experience. Some would say that this means that my religious experience is “just in my head” and of course it is, because it in that sense all my experiences are just in my head! What we call “external” experiences are events that our minds report to us as having an external stimulation. My experience of God is in that way like all my experiences: my mind reports that a being, God, is speaking or moving within me.
Unless I begin to doubt my sanity, there is no good reason in my own experience to doubt that God exists. I could be fooled and sometimes am by the experiences, but my experiences of God have happened all my life, are like those reported by other people I trust more than myself, and do not happen when I am “out of it.” The skeptic demands “proof” that God exists, because he or she cannot “see” what is in my mind and verify it.
If God exists, then we might experience Him (though He could have hidden from us). The nearly universal human experience of the Divine (something greater than self, personal, and other than we are) could receive any number of explanations, but my suggestion is that we two have no reason to reject the simplest one: He is there and He is not silent. One warning: sometimes people bog down in defining things before they discuss them. Definitions can be useful, but we can know a thing or point it out without an airtight definition. I can watch my television without having a very notion of how it works, what it precisely does, or how to define it in a “dictionary” tight way.
By God for just now I mean the Being you and I both feel when we pray. That is at least as good a working “pointer” to what we are discussing we have for many persons. I know my wife, but good luck defining who (exactly!) she is.
There are (of course!) several ways to respond to what I have said so far and I look forward to hearing from you.
Under the Mercy,