The Heavenly Trio is the Seventh-Day Adventist Church’s novel concept of God that they call a Trinity. This is coming from their prophetess Ellen G. White who said…
“The Comforter that Christ promised to send after He ascended to heaven, is the Spirit in all the fulness of the Godhead, making manifest the power of divine grace to all who receive and believe in Christ as a personal Saviour. There are three living persons of the heavenly trio; in the name of these three great powers—the Father, the Son, and the Holy Spirit—those who receive Christ by living faith are baptized, and these powers will co-operate with the obedient subjects of heaven in their efforts to live the new life in Christ.”—Testimonies for the Church Containing Messages of Warning and Instruction for Seventh-Day Adventists, pg. 63 (SpTB07 63.3)
In Adventist theology, the term person is not defined the way the Christian church uses it (ie: the ability to will, self-reflect, speak, be spoken to, etc.) but, rather, refers to having a “literal, tangible form” like we have. They use the terms “person” and “being” interchangeably and affirm three different beings who are “one” in a mission, purpose and character.
The Adventist Heavenly Trio is not one Divine Being expressed in three co-equal, co-eternal persons, but rather is three divine persons who are all separate beings, with the Father being the Almighty (almost like Monarchianism).
Furthermore, the pioneers of the SDA Church were staunch anti-trinitarians, including Ellen White’s husband, James, who notoriously said it was an “old trinitarian absurdity that Jesus Christ is the very and Eternal God” and that the Nicene creed is “an old unscriptural Trinitarian creed.”
Because Ellen G. Whites writings function as divinely inspired documents just like the scriptures, the Adventist Church must remain inline with what she wrote which is more akin to a mix of tritheism and monoarchianism than orthodox, Christian Trinitarianism. In fact, they explicitly reject orthodox, nicene creedal Trinitarianism. The Heavenly Trio is not the Trinity. It is a different god.