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.
And this necessarily altered the relation between humanity and nature. This world, it was now believed, was neither mere base illusion and "dissimilitude," nor a quasi-divine dynamo of occult energies, nor a god, nor a prison. As a gratuitous work of transcendent love it was to be received with gratitude, delighted in as an act of divine pleasure, mourned as a victim of human sin, admired as a radiant manifestation of divine glory, recognized as a fellow creature; it might justly be cherished, cultivated, investigated, enjoyed, but not feared, not rejected as evil or deficient, and certainly not worshipped.
In this and other ways the Christian revolution gave Western culture the world simply as world, demystified and so (only seemingly paradoxically) full of innumerable wonders to be explored.
What is perhaps far more important is that it also gave the culture a coherent concept of the human as such, endowed with infinite dignity in all its individual "moments," full of powers and mysteries to be fathomed and esteemed. It provided an unimaginably exalted picture of the human person--made in the divine image and destined to partake of the divine nature--without thereby diminishing or denigrating the concrete reality of human nature, spiritual, intellectual, or carnal.
[David Bentley Hart, Atheist Delusions: The Christian Revolution and Its Fashionable Enemies (New Haven: Yale University Press, 2009), p.212f.]