Before the creation of the heavens and the universe, the cosmic ether was still, quiet, and void; and at the same time a kind of primordial chaos, indistinct and shadowy with mixtures of density (which we call "the Tao" or pre-creation ether).
In this cosmic ether appeared a great source of Divine Light called "Thai Cuc" (Monad) or the Supreme Being. The Monad then divided itself into Yin and Yang, the two opposite logos: "Am Quang" (Yin Darkness) and "Duong Quang" (Yang Energy). Yin is heavy, dark, cold, dense, negative, inactive… while Yang is clear, bright, warm, pure, positive, active… Yin and Yang interacted with each other to form heavens and universes, with Yang being the origin of the invisible, spiritual aspect, and Yin being the mother of all visible, physical manifestations. Taoism refers to this as "The Tao begets One, One begets two, two begets three, three begets ten thousands beings; ten thousand beings carry Yin on their back and hold Yang in front, blending these two vital elements (breaths) to attain harmony."
Regarding the formation of the universe, the Supreme Being gave the following message: "After creating the universe, I divided My spirit and with it made all creatures, plants and materials. Everything in this universe comes from My spirit, and therefore has a life. Where there is life, there is Myself even in materials and plants. I am each of you and you are Me."
Everything in this universe are from Yin and Yang. The proportion of Yin and Yang would dictate the properties of each dimension. More advanced souls would enter a dimension which has a higher proportion of Yang and would be lighter, brighter, calmer, more beautiful, and may be called heavens. Less advanced souls enter a dimension which has a higher proportion of Yin, and would be heavier, darker, more burdensome with many cruel souls and may be called hell.
Spiritually, everything in the universe shares a part of the Supreme Being's spirit, which is called Conscience or soul in human beings. Physically, everything in the universe has a visible body consisting of a mixture of Yin and Yang, which is well demonstrated by science under the form of electrons and protons in atoms, the basic common elements of all physical reality including materials, plants, animals, and human beings. In summary, there is a oneness between the Supreme Being, the universe, human beings and every thing. The only difference is that the Supreme Being is absolutely pure, absolutely good, absolutely Yang.
Human beings, not withstanding the spiritual part from the Supreme Being, which as noted is absolutely pure and absolutely good, (and which is called Conscience), have a physical body, which is a mixture of Yin and Yang, and which human beings must cultivate in order to become more and more Yang; clearer, better, purer in thought and physically, thereby drawing closer to the Supreme Being, finally become unified with the Supreme Being. In CaoDai, this distilling process is a product of meditation, vegetarianism, moral practices, prayer, to continually raise the vibrational level of Yang.