If we discard the notion that God has to resemble a human in some ways and has to express human qualities, then we can ask 'what is God?' instead of 'who is God?'.
If we don't imagine God to be human, where to start then? Stripped of its meaning, 'God' is only a word. If we give meaning to this word by considering how most people use it, then we come to a theology. If we give try to give a clearly defined meaning, then we come to a philosophy.
Giving meaning to the word 'God' through developing a theological context has the problem that such an indirect definition will most likely lack clarity and consistency. One the other hand, if we try to give meaning to the word 'God' through philosophical concepts, we might find it hard to relate such concepts to our everyday selves.
One way to define 'God' is to say: "God is the unity consciousness of all existence. The process of becoming one is called Love." This is a decent philosophical definition and can be quite useful. However, the problem can be: what the hell does it mean? Even if particular words make sense, it's not sure they will make sense when put together.
To understand God, we have to work on ourselves in order to be able to imagine better versions of ourselves - so we can understand more refined visions of God better. Of course, a vision of God is not God in the ultimate sense, but at least we get one step closer. Words have severe limitations even for lesser concepts, and much more so in relation to the concept of God.