Although neither Taoism nor Confucianism seem to require a belief in spirits or gods as philosophical systems, both have strong traditions associated with deities, spirits, and ancestors. What are those traditions? Why do you think engaging with a spiritual realm remains important for Taoists and Confucians? How is this similar to or different from Buddhism, which also claims it is not necessary to believe in god or gods in order to achieve enlightenment?
Taoism is a Chinese philosophy and religion based on the Chinese word Tao, meaning The Way. Taoism lays out a "number of concepts and practices that make up" the way to live life ("What is Taoism?"). The types of concepts and practices include "'theories' regarding the body, diet, breathing and physical exercises, uses of herbs, philosophical inquiry and, of course, meditation" ("What is Taoism?"). It should also be noted that Taoists consider Tao to be a force, like an energy force belonging to the cosmic universe, not a god. The Tao does not control the universe; it merely exists and flows through the universe, affecting all ("What is Taoism?"). Since Tao is not considered a god, it may seem confusing to also associate Taoism with gods; however, some Taoist religions do indeed have gods. But unlike one of the Abrahamic religions, Taoist gods do not control anything. They are also described as "very tangible beings" who "walk besides [sic] us, share tea with us, laugh, play and can alter reality" ("Taoism 101: Introduction to the Tao"). In that respect, each Taoist god has its own nature and traits that are worshiped per circumstance or even ceremony. It should also be noted that Taoists classify different forms of energy, such as jing. It's believed that jing is essential energy for human life and humans die when all jing expires; hence, Taoists also believe that if jing can be indefinitely preserved, then achieving immortality is possible ("Neidan"). Hence, Taoists see their gods as enlightened beings who have reached immortality through Tao and are now helping others achieve the same end through acting as guides ("Taoism 101"). In this respect, gods are important in the Taoist religion because gods serve as examples for Tao, The Way.
In contrast to Taoism, Confucianism actually has no deities; however, scholars do argue that Confucius himself did believe in deities and certainly in the spirit world. Moreover, he believed that all agents, including both human and spiritual, were part of a "unified, natural cosmos" (Richey, "Ultimate Reality and Divine Beings," p. 3). Confucius, whose real name was Kong Qiu and was called Kongzi, meaning "Master Kong," lived during the late Zhou dynasty and would have inherited religious beliefs that were typical of the Zhou dynasty, specifically the belief in Shangdi, "The Lord on High," an "all-powerful deity" (Richey, p. 1). As the Zhou dynasty progressed, Zhou apologists referred to Shangdi as Tian, and throughout Kongzi's writings, we see him both trying to align his will with Tian's plus wondering if Tian has abandoned him, showing us his belief in Tian. We also know he defines Tian as corresponding with moral goodness and needing human beings to manifest its will, just like a deity. Hence, it can be believed that Confucius had a belief in the deity Tian that was deeply rooted in Chinese tradition. As Confucianism developed, Tian became associated with li, the word for cosmic principle, which is "inscribed in the human heart-mind" (Richey, p. 2). Therefore, as Confucianism developed, the spiritual realm was not seen as separate from the rest of the cosmos, including human beings; hence, human actions like reading, writing, and performing or listening to music, were seen as enough to transcend human nature. So, while Confucianism does not have deities, it certainly does have a sense of spirituality rooted in older Chinese theology, and it is this sense of spirituality that helps define the point of transcendence for human beings.
In all Asian based religions, the primary focus is reaching a sort of enlightenment through a connection with nature and the body/soul. With Taoism and Confucianism, more is focused on the mind and reaching a more intellectual enlightenment.
Confucianism is centered on being moral and respect. Confucius is known for teaching students to follow their intellectual inclinations. For Confucius, learning to be a human (humans were good by nature) was the goal of living. He called for a strict moral structure, following certain rituals.
According to Confucius, each person should act with virtue in all social matters; family, community, state, and kingdom, to ensure order and unity. Man's virtue in all its forms is called "jen." "Jen" is all encompassing and unable to be defined, in some respects similar to the Tao.
"Not to teach a man who can be taught, is to waste a man; to teach a man who cannot be taught, is a waste of words. The wise will lose neither men nor words." - The Analects
Taoism is centered on an absolute freedom of the mind.
According to Taoism, the entire universe and everything in it flows with a mysterious, unknowable force called the Tao. Translated literally as "The Way," the Tao has many different meanings. It is the name that describes ultimate reality. The Tao also explains the powers that drive the universe and the wonder of human nature. Taoists believe that everything is one despite all appearances. Opinions of good and evil or true and false only happen when people forget that they are all one in the Tao. Therefore, it is the aim of Taoists not to forget, and if forgotten to remember that oneness.
Spirituality in Taoism is a connection and sometimes even worship of ancestors. The focus on honoring the dead has to do with not wanting to forget, but also as a thank you and as a source of guidance in living daily life. In Asian culture, not just in Taoist beliefs, life is centered around the family, and unlike in Western culture where we use a spectrum of guilt and innocence, Asians fall on a spectrum of honor and shame. Honoring the ancestors and connecting with their spirits will bring about honor.
With Buddhism, the focus is more on reaching Nirvana/enlightenment in order to leave this life. Buddhists believe that life is naturally miserable, and that spiritual emancipation is the highest goal (leaving this life). In Buddhism, there is a common belief that karma (the good or bad actions a person takes in life) dictates reincarnation, "being born again" in essence. The state that you live this life will determine the quality of life that you will live again. Buddhism also follows a strict moral code. In Buddhism there exists Four Noble Truths:
They are the truth of suffering, the truth of the cause of suffering, the truth of the end of suffering, and the truth of the path that leads to the end of suffering. More simply put, suffering exists; it has a cause; it has an end; and it has a cause to bring about its end. The notion of suffering is not intended to convey a negative world view, but rather, a pragmatic perspective that deals with the world as it is, and attempts to rectify it. The concept of pleasure is not denied, but acknowledged as fleeting. Pursuit of pleasure can only continue what is ultimately an unquenchable thirst. The same logic belies an understanding of happiness. In the end, only aging, sickness, and death are certain and unavoidable.
Spiritualism in Buddhism is a necessity to escape the misfortunes of human life.
I hope I answered your questions!