Hello Airdude
It is secret in the sense that it can not be seen or verified by anyone, It is a non Biblical prophesy in the sense that all prophesy is for us to witness and know that God has confirmed it by bringing it to pass in the plain sight of Man,
The Sanctuary doctrine does not fit the Biblical mode of prophetic fulfillment, We know that there are still some Prophecies that need to come to pass because we have not wittnessed their fufillment,
The sanctuary doctrine which states that Jesus did not enter the holy of holies of the heavenly temple untill Oct 22 1844 was seen by one man in a supposed vision,
Then confirmed by a false prophetess,
Mt 24:26 Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not.
Mt 24:27 For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
Jesus plainly says do not listen to anyone who says he is here, or there or gone into a secret chamber, Jesus did not come in 1844, Your pioneers said that is because he went into the inner chambers of the temple,
Jesus plainly said do not listen to people like you because we have know idea when he coming, He will just be here, Bang, Just like in the days of Noah,
You have to have faith that Ellen G White is truly a prophetess of God to believe this vision because there is no other way to confirm it,
Not to mention that you have to pretend that the Book of Hebrews was never written!!!!
Heb 9:11 But Christ being come an high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building;
Heb 9:12 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.
Every thing considering the atonement work is written in the past tense, Hebrews was written long before 1844 and the work of Christ as the High priest in the Holy of Holies was then preserved in scripture for us as a finished work,
yours in Christ
deu 58