Ellen G. White, who the SDA Church upholds as divinely inspired and correcting of inaccurate interpretations of scripture, claimed that Satan holds earnest consultation with his angels as to the most successful plan of overthrowing the faith of Seventh-Day Adventists. And in this council session, he strategized how he could attack the seventh-day Sabbath and elevate “the sabbath he set up.”
This is because the seventh day Sabbath is the great question which is to decide the destiny of souls so Satan needs to exalt the sabbath of his creating.
The Bible nowhere says any of this, nor does it even imply such. This is all coming from the Great Controversy Theme. This is insight into how the SDA Church views Ellen White’s writings, though. They are the “lesser light” that sheds extra details onto the “greater Light” (ie: the Bible) that aren’t actually found in the Bible.
This is what we call an “Advent-ism.”