Laozi (Chinese: 老子; pinyin: Lǎozǐ; Wade–Giles: Lao Tzu; also Lao Tse, Lao Tu, Lao-Tzu, Lao-Tsu, Laotze, Laosi, Lao Zi, Laocius, and other variations) was a mystic philosopher of ancient China, and best known as the author of the Tao Te Ching. His association with the Tao Te Ching has led him to be traditionally considered the founder of Taoism (also spelled Daoism ). He is also revered as a deity in most religious forms of the Taoist religion, which often refers to Laozi as Taishang Laojun, or One of the Three Pure Ones . Laozi translated literally from Chinese means old master or old one , and is generally considered honorific.
It is unclear when he left this post. Legend has it that after leaving he decided to travel westward riding an oxen. At this time a purple cloud started to hover over him. Thus this journey is generally referred to as the Purple Cloud from the East (紫氣東來). One day he came to China ’s westmost outpost (函谷關). The guardian of this outpost had heard of Lao Tze, his learning and his westward journey. He specially ordered his underlings to keep their eyes open for Lao Tze and when spotted should reported to him immediately. Upon meeting Lao Tze, he accorded Lao Tze the respects of a student to a teacher and asked Lao Tze to leave some of his wisdom in the form of writing behind. At this point Lao Tze wrote a 5,000 word essay titled Tao Te Ching (道德經). After he finished the essay, Lao Tze continued his westward journey and not to be heard from again.
Keep in mind that since the latter part of the Han Dynasty, bloodline and ranked clans (門第望族) were of utmost important. At one point clan membership was the only requirement for high ranking positions in government (上品無寒門，下品無望族). Capability and learning played no part whatsoever. Yes, this is a caste system. Its meridian was during the North-south period (南北朝). The two most powerful clans were Wang (王) and Xie (謝). Stories had it that during the early Tang dynasty the emperor had trouble finding a spouse for one his daughters as the royal family was ranked six on list of desired matches. Then it is understandable for the royal family of the Tang Dynasty who was very conscientious of its somewhat mixed bloodline to seek direct linkage to a historical Han figure. That figure happened to be Lao Tze. Taoism in turn became the national religion during the Tang Dynasty.
I don/’t think the writings of Lao Tze are related Christianity at all. For starter his writings were just one of the many schools during that particular period of Chinese history when it was blessed with thinkers and philosophers. His writings werenn’t adopted by the Taoists as a counter-weight to the Buddhism teachings until centuries later.