An analogy for the concept of different dimensions:
If a colored picture is projected in black and white (with the strongest contrast possible), the image perceived is a sort of silhouette.
The dark shapes are reminiscent of the shapes in the original picture, but they all resemble each other; a person looks similar to a tree, and a tree looks similar to a rock.
But as hues are added to the picture, whether gray or other colors, the image becomes increasingly enriched and whole.
Each hue and color that is added reveals more distinctions between each shape and layer.
In the previous analogy of the two-dimensional image, people can learn to differentiate at least the markers of the additional dimensions, even when apparently they are not visible.
People who are experts at decoding aerial photographs (in which only two-dimensional shapes and shadows are visible) can tell, for example, that what appears to be a circle is actually a tall building, and what appears to be another circle is actually a well, and so forth.
Similarly, regarding holiness, one who understands can identify the markers and differentiate somewhat between holy and mundane, between light and dark, even in this world.
Rabbi Adin Steinsaltz