We do not need anything else but trepidation, which is the proper attitude towards the Creator. One’s work begins when one becomes able to distinguish between “sanctity” (bestowal) and “impurity” (Klipa, egoism).
To be in sanctity means to constantly worry about the Creator supporting us and allowing us to keep the correct attitude towards His revelation, towards the expression of His love towards us. This concern must constantly dominate a person because if he was to break and leave this concern for a certain second, during a certain state on this path, he would immediately fall into egoism, Klipa.
He would begin to use the Creator’s kind and loving attitude towards him for the sake of his own benefit. When he desires to enjoy the Creator’s love for his own sake even for a second, this already is Klipa.
But when he fears whether he will be able to turn the entire revelation of the Giver’s love into a reciprocal attitude towards Him in order to return the same kind of love and bestowal to Him, this is “sanctity.” This way a person raises himself to a level of “sanctity and impurity” determined by his ability to accept the Creator’s love. When he only does this out of fear for returning the same attitude, this is called bestowal, “sanctity.” But when he himself wants to enjoy the Creator’s love, he considers this an “impure desire,” Klipa.
This is called the “screen,” which he always must preserve over him and concern himself with accepting the revelation of Light, the Creator, only in the “Reflected Light.” This Reflected Light determines the degree of “fear.”
From the 1st part of the Daily Kabbalah Lesson 7/6/2011, Shamati No.38