The SDA Church would not exist had not God raised up a prophet, specifically Ellen White, to establish the foundation of its doctrinal positions.
"One thing is certain: Those Seventh-day Adventists who take their stand under Satan’s banner will first give up their faith in the warnings and reproofs contained in the Testimonies of God’s Spirit." Selected Messages 3:84 (1903). {LDE 177.4}
"The very last deception of Satan will be to make of none effect the testimony of the Spirit of God. “Where there is no vision, the people perish” (Proverbs 29:18). Satan will work ingeniously, in different ways and through different agencies, to unsettle the confidence of God’s remnant people in the true testimony." Selected Messages 1:48 (1890). {LDE 177.5}
"My commission embraces the work of a prophet, but it does not end there. It embraces much more than the minds of those who have been sowing the seeds of unbelief can comprehend." (Letter 244, 1906)
There is something about Ellen Whites gift of prophecy that goes much deeper than her work as a prophet...