1) Dao is beyond word or form
This is emphasized in the first chapter of the entire text: The Dao that can be spoken is not the enduring and unchanging Dao. (Chapter 1) Why is this important in the cultivation of Dao? It is because people often confuse things with their descriptions, which are limited and subjected to change. In the cultivation of this steady and formless Dao, the goal is to realize It, not to fixate on the description(s) of It. Therefore before speaking more about the Dao, Laozi reminds us up front that the following are merely descriptions, do not attach to the words and descriptions, become It instead. This is similar to the Zen master pointing his finger to the moon, do not fixate your attention at his finger, it is (as are the teachings of DaoDeJing) a pointer to the Truth (Dao).
2) Nature of Dao
Here is how Laozi describes the Dao: It cannot be seen, heard, felt, named, and is beyond all forms (Ch.1, 14, 35, 67). It exists before heaven and earth, is the mother and foundation law of the sky, earth and human, is independent, everlasting, and without end (Ch.25). It is impartial and treat everything equal (Ch.5). It is both small (no desire and takes no credit) and big (manifest all things) (Ch.34, 51). It is like a limitless valley/vessel which is the source of everything (Ch.4, 6, 11, 32, 34, 35). It is like water that nurtures everything, and can be found from the lowest/deepest place of the world (Ch.8). It is everywhere (Ch.34)
3) Characteristics of human life identified with the Dao
Apart from being described as an objective reality, the Dao is to be realized subjectively by human being. Those who identified with the Dao have the following characteristics: One puts its “self” last, as if its “self” is foreign (Ch.7). One knows and conquers its “self” (Ch.33). One knows one knows nothing and therefore transcend the sickness of the “self” (Ch.71). One abides and centers in the end of emptiness and stillness, transcended & nonattached (Ch.16, 26, 33, 52). One welcomes any situation (Ch.23). One saves all people and all things, embrace and treat them as valuable assets (Ch.27). One has and need no excess (Ch.29). One acts on the Dao diligently instead of just knowing or talking about it (Ch.41). One is ordinary yet precious, like a jade under coarse clothes (Ch.70).
4) Benefits of Dao cultivation
Why did Laozi recommend cultivating Dao? It is because through cultivating and realizing the Dao, one transcends its “self” and will achieve real longevity: life beyond physicality (Ch.33, 52), will abide in everlasting peace without any trouble (Ch.52), will be freed of hazards to the “self” (Ch.55), and its body will becomes healthy, soft, and full of energy (Ch.55).
5) Pathway to the Dao
With the end point described, Laozi had prescribed detailed methods to cultivate the Dao. First, one seeks to understand and transcend his “self” (Ch.33). One learns about the duality of yin and yang, and abides in the yin (Ch.28). One abides in the center/root, accept things as destiny and as normal (Ch.16, 26). Then one surrenders its “self” until non-self and non-doing (Ch.48). One practices “selfless” living, where one puts its “self” last, and treats himself foreign (Ch.7). One fills the holes where “the self” could arise, and shuts the doors where the mind would scatter (Ch.52). One welcomes every phenomenon without attachment or resistance (Ch.23). One diligently says and acts on the Dao (Ch.41, 70). One fights with kindness, economy, selflessness (Ch.67). When encountering hatred, one dissolves it instead of returning hatred (Ch.79).
6) Barriers along the pathway
What are some of the barriers along the pathway? The main one is the “self”. There is attachment to a “self” doing (not doing) and one could be drawn to forcing and manipulation (Ch.29, 32). As one proceeds, the “self” would claim that it knows through thinking (Ch.71). Deeper inside the self could identify and attach himself as existence (Ch.7), and could attach himself to forms, and names (Ch.1).
7) Theme of DaoDeJing
While some of the description or method may seem abstract or difficult to understand, one could understand all if one get the core of the teachings, which is non-self and non-doing. When one transcends the habit of a “self” claiming ownership and doership, one realizes the state of non-self and acts in the world in non-doing. Body and mental activities goes on, even the individual mind and awareness goes on, but one is identified with the Dao which is beyond yet inclusive of all of the above. In such state, therefore, there is no “self” and no one “doing”. This condition is described in detail in QingJingJing.