In The Zohar, Mishpatim (p 4, Item 11 in the Sulam commentary), it is written, “Come and see, when a person is born, he is given Nefesh from the side of the beast, the side of purity, from the side of those called ‘Holy Angels,’ meaning the world of Assiya. If he is rewarded further, he is given Ruach from the side of the ‘Holy Animals,’ meaning from the side of Yetzira. If further rewarded, he is given Neshama from the side of the Kisse (throne), meaning from the world of Beria. If rewarded further, he is given Nefesh, in the way of Atzilut. If rewarded further, he is given Ruach de Atzilut from the side of the middle pillar, and he is considered a son to the Creator, as it is written, ‘Ye are the children of the Lord your God.’ If further rewarded, he is given Neshama from the side of Aba ve Ima, which are Bina, about which it was said, ‘Let the whole soul praise the Lord,’ and with them, the name HaVaYaH is completed.”
Thus, the perfection of the soul is having NRN from BYA and NRN from Atzilut. This is the perfection that Adam ha Rishon had prior to the sin. Only after the sin did he decline from his degree and his soul was divided into 600,000 souls.
This is the reason why man’s spirituality is called Neshama (soul) even when one has only Nefesh de Nefesh, since there is a rule that when discussing anything, we always refer to its highest level. And since man’s highest level is the degree of Neshama, man’s spirituality is generally referred to as Neshama.
And although each person is born with the smallest degree, they said (Shaar HaGilgulim p 11b), “every person can be as Moses if he wishes to cleanse his actions. This is so because he can take another spirit, a higher one, with the height of Yetzira, as well as Neshama from the height of Beria.”
Now you can also understand our sages’ famous words: “The spirit of the righteous or their souls come and are impregnated in what is called Ibur (impregnation), to assist Him with work of God.”
It is also presented in the Sulam (Introduction of the Book of Zohar, p 93): “The thing is that the donkey driver is the assistance to the souls of the righteous, sent to them from Above in order to elevate them from one degree to the next. Had it not been for this assistance, which the Creator sends to the righteous, they would have been unable to exit their degree and rise Higher. Hence, the Creator sends each righteous a High soul from Above, each according to his merit and degree, which helps him on his way. This is called ‘the impregnation of the soul of a righteous,’ and it is called ‘disclosure of the soul of the righteous.’”
It follows that when it is said that there is no generation without the likes of Abraham, Isaac, and Jacob, it does not mean that they were born this way and do not have a choice in the matter. Rather, these are people who are trying to walk in the path of truth and make the necessary efforts. These people always receive help from Above through impregnation of the souls of the righteous, and they receive strength to climb the Higher degrees.
It turns out that everything that is given from Above is considered assistance, but not without any labor and choice. And the persistence of the world is through these righteous, who extend abundance from Above, and thus there is sustenance Above.