Seventh-day Adventist were traditionally Arians, however, they today the church officially affirms the Trinity.
From the article
THE DOCTRINE OF THE TRINITY AMONG ADVENTISTS from the Biblical Research Institute:
The Early Pioneers
Two of the principal founders of the Seventh-day Adventist Church, Joseph Bates and James White, were originally members of the Christian Connection Church which rejected the doctrine of the Trinity. James White was an ordained minis- ter of that church. When he and Bates joined the Advent Movement, they continued to hold the anti-Trinitarian view which they had learned in the Christian Connection Church.
In 1855 J. White published an article in the Review and Herald entitled “Preach the Word.” In dealing with Paul’s statement in 2 Timothy 4:4 “they will turn their ears away from the truth, and be turned aside to fables” he wrote, “Here we might mention the Trinity, which does away the personality of God and His Son Jesus Christ, ....” 1 Joseph Bates wrote in 1868, “Respecting the trinity, I concluded that it was impossible for me to believe that the Lord Jesus Christ, the Son of the Father, was also the Almighty God, the Father, one and the same being.”
The Position of Ellen White
During the early decades of our church Ellen White made statements which could be interpreted as anti-Trinitarian. She at times referred to the Holy Spirit as “it,”8 and in the context of her description of the fall of Satan, she wrote,
A special light beamed in his [Satan’s] coun- tenance, and shone around him brighter and more beautiful than around the other angels; yet Jesus, God’s dear Son, had the pre-eminence over all the angelic host. He was one with the Father before the angels were created. Satan was envious of Christ, and gradually assumed command which devolved on Christ alone.
The great Creator assembled the heavenly host, that he might in the presence of all the angels confer special honor upon his Son.... The Father then made known that it was ordained by himself that Christ, his Son, should be equal with himself; so that wher- ever was the presence of his Son, it was his own presence.... His Son would carry out His will and His purposes, but would do nothing of himself alone.9
This seems to imply that after the angels were created, they did not know or recognize that Christ was equal with the Father and it took a special “heavenly council” to inform them of this
Summary
The early Adventist pioneers were anti-Trinitarians. In the late 1890s Ellen White published articles
and books in which she made strong statements supporting the Trinity concept, although she never used the word “Trinity.” Because many in the church remained opposed to it, more than three decades would go by before the church at large accepted the doctrine. In 1931 the Adventist Yearbook con- tained a statement of twenty-two fundamental beliefs, one of which was the Trinity.
The 1980 Dallas statement of Fundamental Beliefs again reiterates that “there is one God: Fa- ther, Son, and Holy Spirit, a unity of three co-eternal Persons.”58
Modern Seventh-day Adventist anti-Trinitar- ians seek to recover the heritage of our pioneers in regard to the Trinity. They believe that only after Ellen White’s death did the doctrine of the Trinity enter the church, and that her books have been manipulated and changed. As we have seen the evidence does not support these charges.
While the Trinity is a divine mystery and no mor- tal man will ever be able to understand it fully, the Scriptural evidence clearly indicates the equality and eternal co-existence of the three persons in the Godhead. While human reason may not understand it, by faith we can believe it.
