This new doctrine was not accepted in the SDA church until 1980. We use to be a non trinitarian church.
This is what Ellen White had to say:
“The HOLY SPIRIT is the SPIRIT of CHRIST, which is sent to all men to give them sufficiency,” — MR 14, p. 84
“We want the HOLY SPIRIT, which is JESUS CHRIST.” — Letter 66, April 10, 1894
“but it is the leaven of the SPIRIT of JESUS CHRIST, which is sent down from heaven, called the HOLY GHOST,”
— Manuscript 36-1891
“In giving us His Spirit, God gives us Himself,” — (E.G. White, 7T 273.1, 1902)
“The divine Spirit that the world's Redeemer promised to send, is the presence and power of God.” — (E.G. White, ST, Nov 23)
There is a good website that explain it better than me: https://www.trinitytruth.org/
The doctrine was accepted at the end of the 19th century following the publication of The Desire of Ages. The idea that it was not accepted prior to 1980 is fake news (to put it in modern parlance).
Sis. White wrote in The Desire of Ages that the Holy Spirit is the Third Person of the Godhead (p.671, pub.1898)
In Review and Herald 9th October 1913, F. M. Wilcox stated that the 1st of 15 "cardinal features" of the SDA faith was belief in the "divine Trinity".
You have been misinformed... just because something is written on a web site does not make it true. Just read the book The Desire of Ages.
Amen JohnB thanks for bringing some sense to this discussion
The trinity doctrine is not new as such, but in the Adventist church it is only in 1980 that it became a fundamental belief. Adventist pioneers including EG White did not have it although the trinity doctrine was in the Catholic church and the churches most of the pioneers left (Baptist and Methodist mainly). The Bible does not have the word trinity, much less the trinity doctrine.