Unity remains Present.
In the first moment of time, in the birth of duality and separation, there remains an exact point of balance between any two opposing forces. An exact point of equality between an area of heat and an area of cold, or between any other two polarities, will always be present. The three is a moderator for the forces of change, the fabric of Space that stretches between the boundaries of Time.
Inherent in three is the creative dynamic that composes all things in Space-Time. It represents the three Eternal perspectives, the Trinity of Being. Within Yin, Yang, and the Balance, between the Holy Spirit, Father, and Son, among the Mother, Virgin, and Crone, along with Shiva, Vishnu, and Brahma, the three allows for all of Existence to Be.