Matthew 16:19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
The next obvious question is: Where are the keys of knowledge to be found? Beyond the shadow of any doubt, in the word of God. Thus, if Christ is giving to Peter “The keys” of heaven, and if the Keys refer to knowledge, and since true knowledge is to be found in God’s word, then the keys are literally the word of God, as written in the Bible.
[The Desire of Ages pp 413] The keys of the kingdom of heaven” are the words of Christ. All the words of Holy Scripture are His, and are here included. These words have power to open and to shut heaven. They declare the conditions upon which men are received or rejected. Thus, the work of those who preach God's word is a savor of life unto life or of death unto death. Theirs is a mission weighted with eternal results.
Of critical importance is the fact that it wasn’t only Peter, to whom was given the keys of the kingdom, for everyone who is called by God, and who accepts The Rock as Savior and Lord, are also given a set of “Keys”. Thus, it is an absolute misnomer for anyone to place Peter on a pedestal of authority, because of one misunderstood, and misinterpreted passage.
John 20: 20 And when he had so said, he shewed unto them his hands and his side. Then were the disciples glad, when they saw the Lord. 21 Then said Jesus to them again, Peace be unto you: as my Father hath sent me, even so send I you. 22 And when he had said this, he breathed on them, and saith unto them, Receive ye the Holy Ghost: 23 Whosoever sins ye remit, they are remitted unto them; and whosoever sins ye retain, they are retained.
May God add His blessing to the study of His word. “Good night” and God bless!