The traditional faith of the church says that God is eternally Father. For some this is just patriarchal mumbo-jumbo, but despite the masculine language it says something very important. This is clearer if we look first at the alternative propounded by the heretics long ago. If God is not eternally Father, then there must have been a time when God was not Father. That is, there was a time when God was 'alone'. The Son is not, then, of the same calibre of divinity as God the Father, because the Son comes into existence and only then does God become Father. If we follow this through the whole Christian gospel begins to unravel to the point that there is virtually nothing left discernibly Christian. The Son is no longer the revelation of the Father, but God remains the shadowy figure behind the Son. A prophet perhaps, but not God in the flesh, and therefore not the human face of God. It also means that in the case of God relationship is 'added on' to God at the creation of the Son, and is not integral to divinity.And as we are made in the image of God, this would mean that we are at root individuals before we are persons in relationship. How very lonely, like the God who is alone.
But if God is eternally Father then there must be an eternal 'child', and in the traditional language we have inherited, this means an eternal Son. Relationship then lies at the heart of what it means to be divine. (And remember, this is important because we are made in the image of God.) And if this Son has become human, actually human, then this Jesus is the human face of God. God is not now a shadowy figure behind Jesus, but in Jesus we have a real and true encounter with the living God, and this encounter in the flesh.