Yetzirah (also known as Olam Yetsirah, עוֹלָם יְצִירָה in Hebrew) is the third of the four worlds of the Kabbalistic Tree of Life, after Atziluth and Beri’ah and before Assiah. It is known as the “World of Formation.”
“Yetzirah” as in “formation” is in opposition to “Beriah” as in “creation”: actually taking any matter that was created in “Beriah” and molding it into the basic elements.
On the Tree of Life diagram, the Yetzirah is associated with the sefirot Chesed, Gevurah, Tiferet, Netzach, Hod and Yesod. Together, these six sefirot are known either as the Microprosopus (Zeir Anpin) but also as the “Lesser Face” or “Little Face.” In this sense, it is contrasted with the Macroprosopus (Arich Anpin).
The moment of formation, when the form of the fetus becomes evident, is called “the formation of the child” and corresponds to the Yetzirah World. The external state of consciousness in the World of Formation is called the “good half and bad half.” The “good half” refers to the emotional sensitivity of one to the other, expressed in the genuine desire to make the other happy. This outer dimension of Yetzirah is the seat of the emotion that is ignited.
A more internal dimension of Yetzirah, based on the realization that the real battleground between good and evil is within us, is the emotional imperative to pit our inclination toward good against our inclination toward evil. But in order for our good inclination to be victorious over our evil inclination, it must first be empowered by an input of Divine light and energy. GOD gives us this input in the merit of our first devoting ourselves to doing good to our fellow human beings.
The consciousness of the Yetzirah world is that of communion with GOD, speaking with Him directly in prayer or indirectly through the study of His Torah.
Non-permanent angels reside in the world of Yetzirah, unlike the archangels who reside in Briah.