David Bentley Hart explains why God's transcendence over the creation and His immanence within it makes all the difference in the world. This is one reason why the Christian religion is not one religion amongst a smorgasbord of faiths, but the One True Faith before which all other religions are idolatrous perversions of the truth.
Christian thought taught that the world was entirely God's creature, called from nothingness, not out of any need on his part, but by grace; and that the God who is Trinity required nothing to add to his fellowship, bounty, or joy, but created out of love alone.
In a sense, God and world were both set free: God was now understood as fully transcendent of--and therefore immanent within--the created order, and the world was now understood entirely as gift.