When asked of the identity of Jesus, Peter made the confession, “Thou art the Christ, the Son of the living God” (Matthew 16:16). Upon this bedrock truth Jesus promised to build His church (Matthew 16:18; cf. 1 Corinthians 3:11). Then immediately Jesus said to Peter, “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” (Matthew 16:19). There is no change in topic here, for the church of Christ is the kingdom of Christ; therefore, it is natural for Jesus to speak of the kingdom when a discussion of the church is ongoing.
Keys give access. Jesus was saying that Peter would serve a function of giving access to the realm of the saved: the church. Nowhere in this promise is Jesus stating that Peter would pass the keys to the next generation and start a line of authority for humans to preside over Christ’s kingdom and continually revise the doctrines and practices of the church.
Peter would open access to the kingdom. Others had been attempting to control access to heaven, but only Jesus had the right to grant access (Revelation 3:7). Jesus pronounced a woe to the scribes and Pharisees, “for ye shut up the kingdom of heaven against men: for ye neither go in yourselves, neither suffer ye them that are entering to go in.” Luke’s account mentions the key, “Woe unto you, lawyers! for ye have taken away the key of knowledge: ye entered not in yourselves, and them that were entering in ye hindered” (Luke 11:52).
Jesus expounds on the keys in Matthew 16:19 explaining, “and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.” To “bind” and “loose” are terms that relate to matters of law. Even today we say, “this contract is binding.” Thus, Jesus is saying what God had determined regarding transgressions of His law in heaven and pardon would be declared by Peter. In fact, two chapters later, Jesus uses the terms “binding” and “loosing” again in regard to forgiveness of sin (Matthew 18:18). Peter and the other apostles were not making up laws, but rather revealing God’s terms of forgiveness for all (2 Peter 1:16-21).
In Acts 2:38, Peter, on Pentecost day, declared the terms of pardon to the Jews who were guilty of crucifying the Lord by stating, “Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.” Not only did he function as the key bearer to grant access to the Jews, but also later to the Gentiles (Acts 10:47-48).
The way of forgiveness has been opened to all. All may enter the kingdom if they will respond to the terms laid out in the gospel by inspired men such as Peter; when they do such they are added to the church, the kingdom (Acts 2:47). Contrariwise, those who reject the inspired message of the New Testament will remain in their sins and be shut out of the kingdom of heaven (Matthew 25:10-12).