Denys Turner mounts  a defense of Julian Norwich’s notion that between God and our essential being there is no difference. He also provides a helpful gloss on how we conceptualize this distinction or the lack thereof.

Julian writes,

And I saw no difference between God and our essential being, it seemed to be all God, and yet my understanding took it that our essential being is in God: that is to say that God is God, and our essential being is a creation within God; for the almighty truth of the Trinity is our father, he who made us and keeps us within him; and the deep wisdom of the Trinity is our mother, in whom we are all enclosed; and the great goodness of the Trinity is our lord and in him we are enclosed and he in us (LT, 54).

Julian concludes this section by stating “it is no less than a right understanding with true belief and sure trust of what we cannot see, that in our essence we are in God, and God in us.” As Turner explains, much hinges on what Julian means by our ability to see or not see the distinction between God and the soul.

Julian is quite right: the distinction between creature and Creator is impossible to see. But this is not because the distinction does not exist. On the contrary, it is because it is too absolute, too total, for our minds to grasp. Our minds can take hold only of finite distinctions that obtain between things that differ in this or that respect. I can literally see the difference between red and green because they differ as colors do. I can see, in the sense that I can conceptualize, the distinction between what it is for something to be red and for something to be circular because they differ as colors and shapes do. Differences can be discerned only against shared backgrounds in the manner that colors and shapes differ as characterizations of surfaces. But we cannot discern in that way the difference between God and creature, not because that difference is reduced to zero, but because it is maximized to an infinite degree, that is to say, because there is not and cannot be any common background between God and creatures against which their distinction can be measured. The phrase “infinite degree” makes the point. “Infinite degree” is an oxymoron: infinity is not a “degree” at one end of a continuum occupied at the other end by the finite. To be on a continuum of any kind is to be finite. The infinite is off every posible scale (whether of comparison or contrast) with the finite… 

[Julian] can insist that the distinction between God and our substance is imperceptible, because God and our substance do not and cannot differ as kinds of things differ, since God is not a being of any kind, cannot belong to any species. Julian can say that in our substance we are all that God is, for we are as creatures all that God is as Creator, that is, in our substance we are not distinguishable from God – except infinitely (179-80).