Jude 1: 8, 10-13:Now Korah, the son of Izhar, the son of Kohath, the son of Levi, and Dathan and Abiram, the sons of Eliab, and On, the son of Peleth, sons of Reuben, took men: And they rose up before Moses, with certain of the children of Israel, two hundred and fifty princes of the assembly, famous in the congregation, men of renown: And they gathered themselves together against Moses and against Aaron, and said unto them, "Ye take too much upon you, seeing all the congregation are holy, every one of them, and the LORD is among them: wherefore then lift ye up yourselves above the congregation of the LORD?"
It is instructive to note that, according to inspired Scripture, the sin of Korah is possible under the New Testament. St. Jude characterizes this sin as "speaking against" (v.11) or "gainsaying" (KJV) a higher authority. When we read the original account in Numbers 16 we see that Korah's rebellion was based on the presumption that since all the people of God are holy, none can be endowed with a holier office above his fellows. On this view there cannot be gradations of holiness; you're either holy or you are not.Likewise also, these filthy dreamers defile the flesh, despise dominion, and speak evil of dignities... But these speak evil of those things which they know not; but what they come to know naturally as brute beasts, in those things they corrupt themselves. Woe unto them! For they have gone in the way of Cain and have run greedily after the error of Balaam for their reward, and perished in the gainsaying of Korah. These are spots on your feasts of charity when they feast with you, feeding themselves without fear. Clouds they are without water, carried about by winds; trees whose fruit withereth, without fruit, twice dead, plucked up by the roots; raging waves of the sea, foaming out their own shame; wandering stars to whom is reserved the blackness of darkness for ever.
The Protestant priesthood of all believers doctrine teaches that God is "equally accessible to all the faithful, and every Christian has equal potential to minister for God" (from the Wikipedia article). In principle, this doctrine gainsays the presence of any spiritual hierarchy as well as any distinctly ordained priesthood within the Church.
By entertaining this belief, men like Martin Luther and the early Plymouth Brethren saw the way clear to schismatize from the Church and establish the separate communities that they called "churches" or "assemblies."
The Protestant priesthood of all believers doctrine is the ecclesiological corollary to their soteriological principle of justification by faith alone. The Protestant doctrine of justification teaches that the individual may intentionally bypass the binding and loosing power entrusted to the Church through St. Peter (Matt. 16: 19; cf. John 20: 22-23) and come directly to Christ to receive the forgiveness of his sins.
By this, Protestantism has deceived millions of innocent souls, exposing them to mortal danger.
Just because a person can purchase a Bible from a bookseller and read therein that the forgiveness of sins has been made available through the death of Christ, it does not follow that the authority to pronounce absolution has been conferred to his private judgement.
Our Lord Jesus Christ conferred the binding and loosing power once and for all upon his Church after his resurrection. He does not confer this power anew from Heaven immediately to every person who exercises faith. The keys of the kingdom were given when Christ was on earth and have been transmitted down through every subsequent age by the successors of the apostles.
The remission of sins is not received irrespective of the communion of the saints and the hierarchy that structures it.
The Protestant doctrine of the priesthood of all believers participates in the error of Korah, and should therefore be rejected as inherently seditious and, hence, unbiblical.