It is to the Divine Essence just such a limitation as Time is to the mortal. Separation is therefore the antecedent cause of all limitations. These must exist where the Wholeness or Holiness is absent.
I must use the language of earth or you would not understand. Logically, of course, Holiness can never be absent, since it is the cause of all Existence; but it is apparently absent, and this apparent absence, this separation, this evil in fact, acts as a spectroscope. It analyses, and thus brings into our consciousness the White Ray of the Divine Nature.
We can go no further than that. The Divine Chemistry, beyond this fact, must remain a mystery, probably for ages to come.
We cannot tell why things are thus arranged; we only know that it is so.
As well ask why the White Ray of Light gives out its colours only through separating them.
But it is easier to speak of the co-ordination of events. Take your own suggestion of the cube—that will help us best.
Take it that each life is a cube of planes, of experiences. These experiences are co-existent and knit together, as firmly in the life of a human being as the many planes are co-existing, and knit together in a mathematical cube. You can dissect the cube and slice off infinitesimal small planes in sections.
So is the individual life sliced off into an infinite number of planes by the sequences of Time (our three-dimensional condition).
But these experiences—great or small, important or trivial (from your point of view)—exist in the cube of that person's earth pilgrimage, as the colours exist in the White Ray.
The Ray may be split up into sequence, but the colours belong to it all the same, and by a perfectly seeing eye would be known and recognised without the help of the spectroscope.