A couple of things.
One is panentheism.
This is different from pantheism - which is God is the cosmos, and we find God in the natural world (primarily), in everything that is. Most expressions of the wonder of the universe as revealed by science such as the famous one by Carl Sagan are are version of pantheism.
Panentheism understands God as not only comprising the whole cosmos but also outside/before it. The cosmos is made out of God, it is created and sustained by God's will out of God's being, but God is more than the cosmos. God exceeds whatever God has created - which is bound by time and space, whereas God is not - and God sustains what God has created as a free and loving self-giving gift.
This leads us on to the second thing, which is apophatic theology.
Apophatic theology is the attempt to understand God by saying what God is not. I've just done a bit of it: God is not bound by time and space (although we are, so inevitably we reach for terms like 'outside' and 'before' because we don't have any other way we can think). God is not created - he is uncreated, the ground of all possible being. God is not in his cosmos - he is not an entity - the cosmos is in him/her/it.
Eastern Orthodox Christianity has a long tradition of apophatic approaches to God which emphasise the otherness and mystery of God, although it is a strong current in all varieties of Christian mysticism. This approach tends to emphasise the inadequacy of human language to conceptualise God, hence the recourse to metaphors and analogies, such as those by Giles Fraser that you quoted in the OP.
That is one approach to God. The other is to see God in Jesus. Jesus is all human, he's entirely and completely a human being; and he is also all God, entirely and completely the exact imprint of God's nature. That's the amazingly simple yet extraordinarily difficult-to-get-your-head-around heart of Christianity. Christians look to the personality and character of Christ because he is what a person who is totally open to, totally oriented to, without any separation from God would look like.
I'm sure I've recommended it before, but Rowan Williams's Tokens of Trust is an excellent, theologically sophisticated but clearly written book about the nature of God.