The Seventh-Day Adventist flavor of relative truth and progressive revelation is called “present truth” which is the belief that certain biblical truths are relevant to God’s people at specific times in history—that God sends the Holy Spirit to reveal truths that help people better understand how to interpret and apply the Bible in a present day and age.
SDA historian George R. Knight, in his book A Search for Identity: The Development of Seventh-day Adventist Beliefs writes:
Joseph Bates and James and Ellen White (the three founders of Seventh-Day Adventism) each had a dynamic concept of what they called “present truth.” The use of that term wasn’t unique to them. The Millerites earlier had employed it to refer to the imminent return of Jesus (MC, Aug. 24, 1843, 8). Later, they applied it to the “seventh-month movement” (i.e., the proclamation in the autumn of 1844 that the Second Advent would take place on October 22 of that year [VT, Oct. 2, 1844, 144]). Thus even in the Millerite use of the term “present truth” we find a progressive dynamic in understanding.
George R. Knight, A Search for Identity: The Development of Seventh-day Adventist Beliefs, pg. 19
The verse most readily used to support this, as even George Knight notes, is 2 Peter 1:12, which, ironically, is saying the opposite of the Adventist claim.
Peter uses the Greek word estērigmenous here, which means “fixed,” “established,” or “strengthened.” By “present truth” Peter is actually speaking of a fixed fact. Those that Peter was writing to didn’t need to know something different than they already did to live for Christ. This verse also segues into Peter’s soon coming death mentioned two verses later (2 Peter 1:14). Peter was reminding the church to hold fast to the teachings of the Apostles, even after Peter is gone, which is the same call to us today—hold fast what the Apostles deposited. Christians today have this same truth handed down to them in the Holy Scriptures.
Unfortunately, this is a classic case of the SDA Church committing what is called “word association fallacy,” a common occurrence for them. They see the term “present truth” and insert their teaching into the words versus pulling out of the phrase Peters intended meaning.
Much like the other movements of its day who all had their own version of “present truth,” this is how the Seventh-Day Adventist Church is able to spin the failed prophecies and scriptural mishandlings of Ellen G. White (their prophetess) into not being erroneous. They will claim that more light has supposedly been given since then giving further clarity forming new “present truth.”
In reality, it is relative truth used as an escape hatch in problematic theological dealings.