The 'Tao' is an indescribable abstract. Since I enjoy a challenge, I'll try to describe it. Though some of the concepts of 'Tao', can be described, this is not a description of the Tao itself. The Tao is a holistic concept; where one must understand many of the parts to understand the sum.
Taoism is a philosophy of harmony and balance with nature and self. The word 'Tao' means path, road or way. It can be interpreted as method, principle or doctrine. The 'path' is the harmony and orderliness of the universe, it is this manifestation of 'Tao' that is the "natural order" or "heaven on earth". A person need not strive to achieve the Tao, one just yields to the natural forces and follows the path of nature and Taoism.
A symbol of Taoism is Yin & Yang. The symbol is a circle created of two balanced forces (curved teardrops of opposing colors). One teardrop is white (Yin) and the other is black (Yang), but within the Yin (white) there is a little Yang (black), and within the Yang (black) there is a little Yin (white). This symbol represents soft and hard, light and dark, feminine and masculine, and the other balances in life and nature. Yin & Yang is not meant to represent good vs. evil, that is more of a western concept. How can one say, "light is evil compared to dark", when they are both just what they are? They are each fulfilling their nature.
Taoism (and the martial arts), seek to strike a balance between all of the opposing forces in life. These forces are not static, but the dynamic ever changing flow of nature with neither force able to eliminate the other. One does not try to resist this flux (dynamic flow of nature) a follower accepts and let the Tao flow around (and through) them. When in a situation/life you must remember that no matter how bad things are, they will get better; and no matter how good things are, it will fade. Taoism denies material greed and admonishes one to enjoy the pleasures of work, instead of any materials acquired. These aspects of Taoism make it difficult to accept in modern goal oriented society. However, there is a balance between being materialistic, and denying all possessions. There are ways to acquire "things" without placing so much value on them that we are losing our balance. A Taoist would not tell another where to place his personal balance, that is for each individual to decide for himself.
❝Better stop short than fill to the brim.
Over sharpen the blade, and the edge will soon blunt.
Tao Te Ching
To "Become One with the Tao", one does not strive, one simply yield's to it. When you try to hold sand, you do not grab it; because the tighter you grasp, the more you squeeze through your fingers. If you want sand, you make a cup of your hands with palms up and let gravity (nature) help you hold the sand.
Achieving "the path" lies in the thought "Yield and Overcome". Rather than resisting, one accepts natural action (Wu-Wei), which allows you to work with nature and not against it. Rather than being an immovable object, and colliding with unstoppable force, we are the mobile object that diverts or avoids the unstoppable force. In arguments or discussions, in fighting or defense, in learning or teaching, the more you resist, the more you get resistance. If you are too busy attempting to "win" an argument, you may loose an opportunity to learn. This is the teaching of the Tao.
These ideals hold true throughout martial arts and life. Finding this balance can be helpful throughout every facet of life. Martial arts do not try to tell others where the balance is, it tries to teach people how to find the balance for themselves.
Taoists believe "do everything to the best of your abilities" but also learn to "go with the flow". Do not be an interference, if we just sit back and let nature run its course, everything will come out right. Nature will impose its will if we let it, through our own inaction. If one resists the Tao, the results are chaos and disaster.
There is much more mysticism associated with Taoist teachings. Much of this mysticism probably came from the culture of the Chinese people adding mysticism to Taoism, not an inherent mysticism in Taoism. The Chinese people are heavily into mysticism, and this was influenced their beliefs. But then all cultures seem to have their own supersitions and mystical beleifs.
Lao Tsu was the (mythological) "founder" of Taoism. Being dissatisfied with the chaos and strife of his times, he decided that the solution was in a abandoning societies values and emulating the ways of nature.
Lao Tsu wrote the Tao Te Ching (Pronounced Dow De Jing), which is a book of poetry about Taoism, with eighty-one chapters (poems). Later the "Inner Chapters" of Chang Tsu were written, to further enlighten people to the Tao. There are seven "Inner Chapters" which are believed to be written by Chang Tsu. There are also twenty-six additional chapters that are believed to be written as "aids" or "additions" (commentaries) by later authors.
A simplistic understanding of the Tao can been understood by watching the Movie Series "Star Wars". George Lucas studied Taoism and Eastern Philosophy for quite a while before he made these movies. This is quite apparent to those who have also studied. Through out the film we hear tales and learn the values of the "Jedi Knight" and of "The Force". What George Lucas did was introduce Americans to Bushido and the Tao, to Martial Arts philosophy, and to eastern philosophies in general, all camouflaged in SciFi mumbo-jumbo.
The Jedi worked on many aspects of their person, including meditation, mental exercises, learning how to deal with their problems, learning how to defend themselves, and in keeping fit. This is the values of Bushido, and Martial Arts in general. The martial artist attempts not only to improve his "fighting" skills, but all the things that can make him as a better person.
The "Force", as it was called in the film, could have as easily been called the Tao. Obi-Wan described the Force is “an energy field created by all living beings.” And Luke Skywalker was taught to not fight "the force", but to feel and accept it around him. He was taught by the wizened master, that through accepting the power of the force (nature/tao), and learning not to doubt himself, many things were possible. These are very consistent with the teachings of the Tao.Then later, Lucas fucked it up by trying to mansplain how the Jedi utilized this force as "Midichlorians". All of a sudden, instead of there being an energy field that “binds the galaxy together,” there are little microscopic life forms (symbiotes) inside of the Jedi, allowing them to connect to this energy field that was all around us? This was one of the dumbest contradictions since claiming the Millennium Falcon made the Kessel Run in a measure of distance (instead of time).
So there is no deity in Taoism, other than nature. There is a book, but it is a book of poems to hint, not rules to mandate. There are many prophets and teachers. There are some that take the concepts into a religion; where if you study the Tao and merge with nature enough, that you can live forever or do impossible things. But most aren't looking at those things as any sort of ends; it is just a demonstration of the means and power of nature. Followers are striving for humility and blending, not power and conquering. Or as they say; the ocean is the master of all streams and rivers because it lies beneath them. This represents that the ocean is below (more humble) the rivers, yet all rivers must yield to nature (and gravity), and eventually flow to the ocean. This is the way of the Tao.
These articles came from a book (student guide) I wrote on Martial Arts in the 1980's.