「三清道祖」是道教最高之三位神祇，亦合稱三境天尊。三清在六朝時本來是指三清境，也就是玉清、上清、太清三個地方的合稱，因為他們是道教三位至高神各自的居所，所以逐漸變成以地名代表道教的三位至上神。這三位至高神即元始天尊、靈寶天尊和道德天尊，道德天尊。元始天尊居於玉清聖境清徵天，又稱元始天王，即盤古。靈寶天尊又稱玉晨道君、無形天尊天寶君、無始天尊靈寶君，居上清真境禹餘天；道德天尊即太上老君，又號梵形天尊神寶君，居於太清仙境大赤天。
「元始天尊」即元始天王，又稱「虛無自然洞真元始天尊」，是道教的最高神。據陶弘景《真靈位業圖》，元始天尊居住的玉清境，是在諸仙所居處的「玉清三元宮」裡「上第一中位」，也就是三十六天最高位。玉清境有紫雲之閣，以碧霞為城，眾神仙要按時朝覲元始天尊，諸仙向元始天尊上號為「玉清紫虛高上元皇太上大道君」。
「靈寶天尊」又稱「上清大帝」，是三清中之第二位。在陶弘景的《真靈業位圖》稱「上清高聖太上玉晨玄皇大道君」，簡稱「太上道君」、「玉晨道君」。靈寶天尊是元始天尊的化身，位三清尊神之第二位，雖然早期有相關的文獻記載，但六朝時期道教造像史中，關於靈寶天尊的資料甚少，推測靈寶天尊的造像，可能是較為後期的發展。
「道德天尊」就是老子，也稱為老君，是一般大眾熟悉的道家人物，根據早期的造像史料顯示，老子本來代表道體，他「生於無形之先，起於太初之前」，能浮游六虛之中，觀察混沌未判的情狀。張道陵、寇謙之也皆宣稱所得之道法源於老子下降親傳而得。老子在早期道教的重要性可見一般。隨著早期道教教義的發展，在陶弘景的《真靈位業圖》位居第四位，最後定型成為三位至上神之一。
此外，三清也被賦與各種不同的意義。一説三清分別代表道教發展過程中三個重要的傳承，元始天尊代表上清派、靈寶天尊代表靈寶派、道德天尊代表天師道。一説三清即「道、經、師」，是為道教中的三寶。根據陳觀吾為《度人經》所作之註，「道」是指元始玄一之祖炁，即元始天尊，祂生出天地人物。「經」是由玉晨道君所演之元始玄一之道，玉晨道君也就是靈寶天尊，道法於道教而言乃是萬世的梯筏。「師」則是太上老君，因為他降授張天師以經籙，使之得以傳世流佈。此外，因為三清在哲學意義上是元始的一氣所化，所以祂們也主宰人的精氣神。
三清殿是道教宮觀的主要殿宇，主祀三清道祖。元始天尊居於中間，左手手訣，右手持混元珠，象徵混沌未明之際。靈寶天尊居於左側，手捧如意或太極圖，代表混沌已明。道德天尊神手執太極扇，居元始天尊之右側，象徵陰陽已明，陰靜陽動。各地的道教宮觀如高雄道德院、宜蘭道教總廟三清宮等皆以三清道祖為主祀神。在各種大型道教齋醮禮儀中，內壇也設有三清神位或神像。元始天尊的神誕之日是正月初一。靈寶天尊之神誕日為夏至日，約在農曆五月中。道德天尊之神誕日為農曆二月十五日。
關鍵詞：三清、三清道祖、醮
李龢書。2009。〈早期道教中的道與至尊神〉，（台北：台灣大學歷史研究所碩士論文）
李龢書。2008。〈從老君到天尊：對北朝天師道教團發展史的幾點觀察〉。《政大史粹》， 15：1-52）。
卿希泰主編。1994。《中國道教》（上海：新華）。
Sanqing daozu (三清道祖), Three Pure Ones, are the three highest gods in Daoism. Daoist thought that the creation of universe is the result of their works. In Six dynasties, Sanqing (三清) originally denoted the place where Three Pure Ones live in. They are three places in the heaven. According to Daoist cosmology, there are more than 30 levels in Heaven. The highest one is Yuqing jing (玉清境) , the second is Shangqing jing (上清境), the third is Taiqing jing (太清境). Sanqing dao zu are Yuanshi tianzun (元始天尊), Lingbao tianzun (靈寶天尊), and Daode tianzun (道德天尊). Yuanshi tianzun dwells in Yu-qing jing, Lingbao tianzun and Daode tianzun lives in Shang-qing jing and Tai-qing jing separately.
Yuanshi tianzun is Pan gu (盤古). He lives in Yu-qing jing, the jade pure, where a purple cloud is around his palace. The cloud with bright green color is surrounded the palace as the wall. All of the Daoist immortal in heaven should periodically have an audience with Yuanshi tianzun on schedule.
Lingbao tianzun is the hua shen (化身), the “avatar” , of Yuanshi tianzun. Though his title and dwelling place was recorded, his statue was rare before Tang dynasty. It seems his character was not very clear in early Daoism. Daode tianzun is Lao Zi (老子). However, he is not the philosophical Lao Zi but the religious one who is not very well known today. At first, early Daoists regarded Lao Zi as the symbol of the natural of Dao. He was born before nothing and rose up when the very primitive universe had not begun. The famous Daoists, such as Zhang Daoling (張道陵), Kou Qianzhi (寇謙之) all claimed that their teaching of Daoist imparted by Lao Zi directly. However, when Tao Hong-jing (陶弘景) compiled the Zhenling weiye tu (真靈位業圖), he dropped Lao Zi down to the fourth place. Until Tang dynasty, because the royal house’s surname is also Li, emperor recovered Lao Zi to the third place. The hierarchy of Sanqing daozu was settled down then.
Besides Sanqing daozu’s arrangement in heaven represents the cosmology of Daoism. In Daoist, they are separately represented the major three schools of Daoism. Yuanshi tianzun represents the Shang-qing school, Lingbao tianzun and Daode tianzun represent the Ling-bao school and the Tianshi dao (天師道) separately. Sanqing daozu are also the symbol of Dao (道), scripture (經) and Master (師). Because the Yuanshi tianzun is the very first, he represents the essence or natural of Dao. Lingbao tianzun is the avatar of Yuanshi tianzun, Dao. He represents the Way which is equal to the scripture or the teaching of Dao. Daode tianzun, as Lao Zi, imparted the teaching directly to mortal human. His meaning is the Daoist, who is the master of people.
All of the Daoist temples dedicated to Sanqing daozu. On the arrangement of Sanqing daozu’s statue, Yuanshi tianzun is situated in the middle. He often holds a crystal ball on right hand. The crystal ball, hun-yuan zhu (混元珠), means the chaos before the universe started. Lingbao tianzun is situated on the left side with a ruyi (如意), a decorative object symbolized as you wish, or a diagram of Tai-ji (太極圖). Ruyi or the Tai-ji means the chaos is becoming clear. Daode tianzun hand a Tai-ji fan with him and situates on the right side. The Tai-ji fan means the Yin (陰) and Yang (陰) being on the right position of universe.
Keywords: Sanqing daozu, Sanqing, Yuanshi tianzun, Lingbao tianzun, Daode tianzun
References:
1. 李龢書。2009。〈早期道教中的道與至尊神〉，（台北：台灣大學歷史研究所碩士論文）
2. 李龢書。2008。〈從老君到天尊：對北朝天師道教團發展史的幾點觀察〉。《政大史粹》， 15：1-52）。
3. 卿希泰主編。1994。《中國道教》（上海：新華）。