From Opposites to Perfection
Nukva (Malchut, the female part) was created out of the desire to receive pleasure. Zeir Anpin (the male part) was created out of the desire to bestow. Zeir Anpin is the Creator (Kadosh Bar Hu) and He does not have a desire to enjoy. He only has a desire to bestow and love.
Nukva consists entirely of the desire to enjoy and is therefore able to become similar to the male part only by overcoming and suppressing her own natural egoistic desire, by restricting and correcting it. That is how she attains equivalence with Zeir Anpin and adhesion with him.
Therefore, Nukva‘s entire work in order to attain unity with Zeir Anpin lies in taking an example from him and being his Nukva, female part, rather than becoming the same as he. For Nukva becoming similar to him means being opposite to Him, "help against him." This is like two interfacing forms with curved shapes: as much as one is concave in one place, the other is convex. Each complements the other along the entire boundary between them, either by "bulging out," meaning having some quality, or "curving in," lacking that quality.
Therefore, Nukva has to remain "help against him." Her work is "against"; it is work in order for both of them to attain the goal. The more they work together, the more they discern the relationship between them, their common goal, and the quality of each of them which is opposite to one another.
Their work is to complement one another. They find perfection only in the third element, the Creator, Bina, to which they ascend by uniting together in ZON only for the sake of ascending into Bina. Perfection is possible only if they acquire a connection with Bina in their mutual unity.
Therein lies a very fine and fundamental point relating to the nature of the Creator and the nature of creation. For creation, becoming similar to the Creator means only completing itself until the Upper One, rather than taking Him as an example and becoming the same as He. I am similar to Him through bestowal, but it is me who is similar to Him based on my qualities, my nature.
Therefore creation remains "help against," and precisely thanks to this each of them attains perfection, independence, and his own status, and both are worthy of respect. Creation does not dissolve or disappear in the Creator, but supplements Him with its opposition. And the Creator becomes revealed precisely by virtue of creation.
With His "concaveness" or lack of any quality, the Creator gives creation the opportunity to express itself and complement Him with its "convexity," the presence of that quality (like an electrical outlet and an appliance plugged into it), and vice versa. That is how they work together.
By completing each other this way they attain mutual perfection. One cannot manage without the other. The Creator needs creation and creation needs the Creator. Only through mutual completion, in the middle between them do they attain perfection.
From the 2nd part of the Daily Kabbalah Lesson 12/19/10, Talmud Eser Sefirot