Introduction
With the birth of the first organized Daoist "church", the already existing deities and new deities  start to be systematized in a pantheon. This pantheon and the ways of communication with it bears strongly resemblance with the human order on earth. This underline the blurred distinction from mundane and supramundane realms, typical of the traditional religious worldview of China.

Pivotal event for the tradition: the historical context of the birth of organized Daoism
By the turn of the millennium, apocalyptic and messianic movements began to emerge in widespread areas of China. For example,in 184 C.E., the Yellow Turban rebels in eastern China tried unsuccessfully to overthrow their ruler, the Han Dynasty.  They based their actions on a sacred text called the Scripture of Great Peace, which described a utopian realm governed by a benevolent sage-king. According to this text, there was a loss of cosmic balance and  people must cultivate their inner Dao in order to restore it.

Main doctrinal traditions: the birth of the Way of the Celestial Masters, the first organized Daoism
In 2nd century CE, a group appeared that shared some characteristics with above cited messianic movement, called the Way of the Celestial Masters. This event marks the formal establishment of the organized Daoist religion. The movement traces its origins to a revelation to the founder Zhang Daoling in 142 CE, when a deified Laozi descended to him and told him to establish a new covenant between the true gods of Daoism and the people, in order to restore the balance. The central feature of its teaching was a rejection of the blood sacrifice offered to the traditional gods of the community and the state in favor of a new relationship between humankind and a newly revealed pantheon of Daoist deities.
The Way of the Celestial Masters are characterized by a strong emphasis on the ritual practices and its membership was open to women and ethnic minorities as well.  Concerning the ethical dimension, differently from the seemingly ethical indifference of the
Zhuangzi and Daodejing  (see p. 3), there was a great concern with sin, which was observed and recorded by dedicated offices and could only be expiated through written confessions submitted to them. This bureaucratic approach is characteristic of many Chinese religious traditions and informs also the Daoist Pantheon.
The Way of the Celestial Masters was originally theocratic in concept, seeking to create a utopian state that would replace the Chinese imperial institution. Although these beliefs faded, the Daoist community structure survived in local communities across China for centuries.  Today, this tradition remains mostly often with the name "Orthodox Unity". The majority of non-monastic Daoist priests both within China and in the Chinese diaspora have identified themselves as part of this tradition.

Deities and other holy beings: the Daoist Pantheon
Daoism is a theistic tradition. Because Daoist worldview centers on emanation and immanence, deities are simply differentiated aspects of the Dao.
The number of Daoist deities  is staggering. The pantheon differs according to sect and region, and its ranks are fluid. In the early days of Daoist religion, deities that preexisted Daoism continued to be important to the Daoist religion, such as the Queen Mother of the West. She is able to teach and confer immortality, and remains a popular Chinese deity today.
In terms of the dominant Daoist schools, only two of which survive in the modern world, Orthodox Unity (a.k.a. Way of the Celestial Masters) altars generally place Jade Emperor or Lord Lao in the highest position. The Jade Emperor is the celestial counterpart to the Chinese emperor of earlier times. He is seen as the ruler of a bureaucratic organized cosmos. Lord Lao is the anthropomorphic representation of the Dao and the deified form of Laozi.
The other contemporary dominant school, the Complete Perfection, tends to be devoted to the Three Pure ones (see below). These “gods” represent the three primordial energies of the cosmos, the earliest moment of cosmic differentiation, whose origin is represented by the god called "Great One".

Main doctrinal tenets: cosmic correlations and communication with the gods
In Daoism cosmos, deities human being, society, and ritual area are analogically related to each other. Deities and features of the world often correspond to one another. For example, The human community with its codes and hierarchies, ideally mirrors the configuration and order of Heaven. Reciprocally, Heaven is an administrative system overseen by the Jade Emperor through bureaucratic procedures similar to those performed at court.
The unity of the cosmos is represented in a deified form by the Great One, who resides at the center of the cosmos in the North Pole, from which distributes the Primordial Qi  to the regions of space and sustains the cycles of time. Several other gods, such as the "emperors" of the five directions, also represent cosmological principles. All can play an essential role in the various ways that Daoism provides for "returning to the Dao". Therefore, also the ritual area is arranged so as to correspond to the cosmos and its temporal and spatial configurations.
Moreover, consistently with the bureaucratic nature of the Pantheon, the typically Daoist form of communicating with the gods is by writing. In the Daoist ritual, the priest delivers a "memorial"  to the deities to announce that a ceremony will be performed in their honor, declare the purpose of the ceremony, specify its program, and list the names of those who are sponsoring it.

Analysis of sources

Source n° 1
Taoist Priest
Taoist priest are called Daoshi, (masters of the Dao). Especially in the Way of Celestial Masters, there  developed a sacerdotal lineage of priests that have married, lived in the communities, and passed on their office hereditary for nearly two millennia. Priest perform active roles in the community, preaching, organizing various rituals which often involved chanting the Daode jing chorally, performing exorcism, daoist medicine and so on.

Source n° 2
Daoist investiture of a local god
As noted above, the Way of the Celestial Masters advocated a new covenant with the true gods, emanations of the Dao. In order to do so, cases of assimilation of already existing, local deities were frequent. Moreover, these procedures were undertaken in a fairly bureaucratic manner.
The first part of the scroll depicts the court of the Jade Emperor with four female attendants, four( two visible) high officials, and two (one visible) groups of other deities. The second part of the scroll depicts the local god with four attendants carrying incense burner. The local god,  is shown larger to emphasize his importance. In the sky above, a heavenly messenger appears bearing the scroll of the god's investiture. The third part is a transcription of the petition made to the Celestial Master requesting to recognized the local god as a member of the pantheon.

Source n° 3
The Three Pure Ones
In in the center is the god called "Celestial Worthy of Original Beginning". On his right there is the "Celestial Worthy of the Dao and Inner Power" and "Celestial Worthy of Numinous Treasure on his left.
"Celestial Worthy of Original Beginning" represents the earliest phase of Creation of the Universe, when from the Dao manifest Unity (the Primordial Qi). Then "Celestial Worthy of Numinous Treasure" separates the Yang from the Yin, and classified the elements into their rightful groups. In the final phase of emanation, "Celestial Worthy of the Dao and Inner Power" is manifested to bring civilization and to preach the law to all living beings.