The Zohar explains how relations between letter and number, earth and heaven, and male and female are structured in the form of a three part structure, or triad.
Before the creation of our universe, the infinite Light of the Creator shared its untold fulfillment with the infinite Vessel: Sharing and Receiving; Two Columns. The birth of our universe occurred when the primordial Vessel-composed of all the souls of humanity-purposely stopped receiving the Light of the Creator for the chance to create its own Light, and thus become the cause of its own fulfillment through spiritual development. This act brought into being a third force, Resistance. These three Columns - sharing, receiving, and resistance - are present throughout every level of reality. In our own lives, we must use our free will as the force of resistance to control impulsive and self-serving drives. As a light bulb glows brightly when the filament creates resistance, so our lives shine brilliantly when we apply restraining force. Life then has true circuitry. The strength and consciousness to live in accord with the three Columns is imbued into our nature by these passages.