A lot of Russell's doctrines were taken from the Adventists. However, Seventh Day Adventists worship the Trinity, so I am wondering who Russell took his Anti Trinity doctrine from. Christadelphians started in the mid 1800's, was it from them?
Who did Russell get his anti Trinity doctrine from?
from the Rothchilds. His relatives.
For Jews, the belief that God can be human is the ultimate heresy.
— Rabbi Shmuley Boteach, on Christianity
Maybe from the Unitarians?
Arianism was prevalent among the Adventists in the mid-19th century, even among the leaders. Arianism entered the Adventists through the Christian Connection, which later merged with other groups to become the United Church of Christ. There is a offshoot of the SDA that is Arian, and they have a website about how the early SDA leaders were Arian. Perhaps I can find it. The Adventist group Church of God of the Abrahamic Faith are Unitarians, but do not believe in the pre-existence of Jesus. They were influenced by the Christadelphians.
Storrs believed that Jesus was God, but believed that the relationship of the Father and the Son was a mystery, and would not characterize his belief as either Arian or Trinitarian. Russell was an Arian in his beliefs like many Adventists of his time. Russell likely got his Arian views from George Stetson. Stetson was an Advent Christian minister who was pastor of the Allegheny Advent Christian Church from 1871-1873. Stetson wrote an article on the Ransom that appeared at the time in the the Advent Christian magazine. He gives the view that the ransom was a corresponding price to Adam. It is on the internet and I can locate if anyone is interested.
The SDA, Adventist Christian Church, and the Worldwide Church of God all made moves toward accepting the Trinity, reversing an earlier anti-trinitarianism.
Pharisaism-Talmudism predates Adventism and the heretic Arius by a long shot. The Pharisees of Ancient Babylon.
Acceptance of the trinity is only a later development within Seventh-Day Adventism which occurred during the 1970s - among most but not all Seventh-Day Adventists. Some other Adventists and many of the independent Bible Students (also children of 19th Century Adventism) do not have the trinity doctrine. And of course neither do JWs which are surely Adventist also.
In The Kingdom of the Cults, Walter Martin takes a very curious position towards Seventh-Day Adventists and blesses them with the non-cult label apparently chiefly because of their acceptance of the trinity doctrine - thus reversing his earlier determination in his 1960 book, The Truth About Seventh-day Adventism.
Arianism which goes back obviously to the roots of Christianity is only one view which rejects the trinity but it is not the only non-trinitarian view.
Jehovah's Witnesses are very clearly a sect of 19th Century Adventism and as such they represent a specific branch of Adventism.
Contemporary JW theology still includes most of the tenets of Adventism and of course central to the theology is the premillenialist eschatology.
Also not to be overlooked is that the three Adventist institutions namely: the press, the general conference (aka conventions), and the association or corporate form (e.g. "the society") still remain fundamental features of Jehovah's Witnesses.
To answer your question, it is uncertain whether Russell developed his non-Trinitarian views on his own, or due to the influence of the cloud of his Adventist associates, or a combination of this.
PS: I recently understood (came upon) for the first time the direct connection from Russell to Miller (aside from Russell's high opinion and references to Miller of course) through the George Storrs - Charles Fitch - Josiah Litch connection. Fascinating stuff. This combined with the others I already knew about such as Barbour, Jonas Wendell, George Stetson and B.W. Keith leave no doubt in my mind that Bible Students & JWs are sects within the Adventist family. (Just as Melton classifies them.)
Great comments, Stev I would love it if you could find the sites.
Russels heressy comes from Arius thanks to whom Church had to define trinity explicitly! JW use this argument actually without knowing they are reminding why doctrine of trinity was explicitly defined. First heressies were gnosticism which were adressed in Pauls and Johns writings, next heresy was Arianism, and then church defined doctrine of trinity as we know it today. The teaching was there even before Arius was born, JW just don't believe what Churhc fathers teached as they do not read the history, and when read - does not believe if Elders do say otherwise.
What I wanted to say - JW teachings war refuted and declared herressy in 4th century!
Gotta agree with Eduardo, here.
The JWs are nothing original. Russell was hugely influenced by the Adventists. It used to surprise me no end, when discussing religion with Adventists on the doors, that they were so similar.