What is apparent from traditional experience is that at the level of the Tzadik, there is no strong feeling of a gap between above and below, between the physical and the spiritual.
The true Tzadik has no sense of a separation between worlds.
He can pray to God and also eat and talk to common people with the same unvarying keenness of interest and total participation.
This is only one aspect of that higher level of being.
Another aspect of this same level is that the perfect Tzadik does the work of God without any thought of self, and, in fact, renounces himself in the doing.
The human and the Divine somehow merge into a single type by a continuous process of refinement, or a sifting of the good out of the Nogah Shell.
This process is also known as the uncovering of "feminine waters" causing "supernal union" and the bringing down of "masculine waters" to facilitate the flow of Divine goodness.
In a certain sense, most of the Divine worship of the religious person through works of Torah and mitzvot consists largely of such a filtering out, or separating the inner substance from the Nogah Shell and raising it to holiness.
For example, consider the act of taking a coin and giving it to charity.
The coin itself is of the Nogah Shell; it is the mitzvah of charity that extricates and lifts up the essential good in it and brings it to holiness.
This raising up of the holy from below is called the elevation of feminine waters.
The raising up of the level of the world, thereby responding to an influence from above called the masculine waters, makes possible a supernal union which results in a downflow of Divine plenty.
Thus, the holy union of God and the Shechinah, which characterizes every mitzvah, is a merging of forces from above and below, and almost all that man does in prayer and Torah consists of such an uncovering of feminine waters, which in turn awakens the higher forces.
The more genuine and sincere one's thoughts and actions, the more this hastens the Divine Union.
That is the difference between an ordinary person and a Tzadik, and especially a complete Tzadik who transforms darkness to light, bitter to sweet. With every step he takes in his life, the Tzadik elevates something into holiness and binds the worlds.
His whole existence becomes such a dedication; and naturally, he will tend to isolate himself from the common world and responsibilities of man in order to better perform his destiny and fulfill his obligation to God.
–Rabbi Adin Steinsaltz
In The Long Shorter Way by Rabbi Adin Steinsaltz