Substantively speaking, God is not a person. And yet, God can only be interacted with as if God were a person.
Paul Tillich was right: if God is the one in which we live and move and have our being–if God is the very ground, structure, and goal of being–then God is not a being. God cannot be subject to the particulars of being for God is the one that determines those particulars.
And yet, in a poetic way, we claim that God has revealed God’s very self to us–the nature of God. We see evidence of God in nature, which shows us much about God, but it is Jesus Christ whom we claim shows us what it is that God intends.
Jesus Christ–a person–shows us how God–a not-person–intends for us to love all of Creation.
landon whitsitt 
De-personalizing God is difficult for me. I have always thought of my prayer life as a conversation with another person, though a divine person. I don’t converse with stars, planets, plants or animals even though their magnificence knocks me off my feet. And I have thought a lot about the question which a subscriber of process theology posed to me years ago, namely, how do we account for a God who feels things and changes his/her mind? This countered the Greek idea that God was changeless, but in the present discussion argues that whatever/whoever is the supreme being has person-like attributes.
I’m with you on the difficulty, but I’ve come to see it as a necessity. If God is the one who determines what it means to be a person, then it stands to reason that God is outside “personhood.”
This is a philosophical claim, not a theological one, though. From a theological viewpoint, I’m not sure we can operate any differently than to relate to God as a person. We would have no other way to do so.
I, myself, once prayed a prayer in which I said, “Look – I know you’re not a person, but I’m gonna treat you like one, okay?” 🙂
It would be wise here, I think, to continue to look beyond TIllich’s categories and recall that although God is beyond being (or personhood) God cannot be excluded from them either without falling into the same problems. God is simultaneously person and that-which-is-beyond-person just as God is simultaneously being and the ground of being.
God’s un-relatability is precisely how we relate to God. It is precisely in the mystery that the mystery is revealed. I think that we can relate to God outside the anthropomorphical categories of personhood, however we have allowed ourselves (and the church?) to lapse into a way of doing theology that lacks imagination and wonder. Our theology has become so concerned with being descriptive that it has failed to be imaginitive. In other words, when our theology is focused on saying, “God is…” we leave little room dream that “God could be…”