Some souls need to correct more in themselves, others need to correct less. However, when they return to the root of their soul, each attains perfection. There are souls that pertain to the main systems of Adam HaRishon akin to the brain, the heart, the liver, and the kidneys, like vital organs of the common soul.
Yet, on the other hand, in perfection, a cell at the tip of the heel is just as important as a cell in the brain. Only in our material world can a person live without an arm, a leg, or some organs. The spiritual world is perfect; therefore, every part is just as important as all the others.
If someone does not complete his correction by even 1%, there will not be general perfection. Even if all the others are already corrected, because of his incomplete correction (< 100%) final correction will not come. It is difficult to understand this spiritual principle: all are equally important, but each differs according to the roots of their souls.
However, when we return to the World of Infinity, no one will feel any differentiation from the others. If one carries out everything that he was obliged to according to his qualities, then, he has realized himself completely.
Therefore, although most souls pertain to the level of Nefesh, a smaller amount pertain to the level of Ruach, an even smaller amount to the level of Neshama, and only some pertain to the complete degree of NRNHY, nonetheless the common Light shines to everyone! The whole Light of Infinity fills everyone in the common, corrected soul.
We cannot understand this in our world with our uncorrected qualities because we exist in such lack of perfection that we cannot even imagine the corrected state of the soul.
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