So far, I have tried to establish the fact that Peter (Petros, a masculine noun for "a small rock or stone") is not the rock (Petra, a feminine noun for "a large rock or boulder"), but that Jesus was speaking of Peter's statement of faith (Pistis, a feminine noun) in Him as the Son of God, which is the foundation for the Church. "For other foundation can no man lay than that is laid, which is Jesus Christ" (1 Cor. 3:11). I have also said that I believe the key Jesus gave to Peter to open heaven's one and only door (Jesus - Jn. 10:7, 9) was the Gospel. The other key open the gates of hell (Matt. 16:18) for the spreading of the Gospel to those who belong to Satan, so "that they may recover themselves out of the snare of the devil, who are taken captive by him at his will" (2 Tim. 2:26).
Today, I want to share what I believe Jesus meant when He said, "...and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven" (Matt. 16:19). Jesus was speaking to Peter. And contrary to the teachings of the Roman Catholic Church, Jesus was not making Peter the first Pope. In fact, most theologians believe that James was the head of the Jerusalem Church (Acts 15:13-18; Gal. 2:12). At that time, to the early Church, there were three groups of unsaved people on earth: Jews, Samaritans, and Gentiles. The first century Church believed that they were to convert Jews to Christ, and convert Samaritans and Gentiles into Jews first and then into Christians (Acts 15:1-5). Paul challenged that (Acts 15:2-5; 12), and Peter reasoned against it as well (Acts 15:6-11), but it was James that made the final decision on what the Church would do (Acts 15:13-21).
And yet it was Peter who would ultimately determine who were to be considered Christians. Moments before Jesus ascended into heaven, He told His disciples to "be witnesses unto Me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth (Acts 1:8). Peter preached on the Day of Pentecost to Jews from everywhere (including Jerusalem and Judaea), and they were filled with the Spirit and becoming members of the Body of Christ (Acts 2:14-41).
In Acts 8:1-13, Philip preached the Gospel to the Samaritans and many accepted Christ. But it wasn't until Peter had witnessed the converted Samaritan's evidence of being filled with the Holy Spirit, that the Church in Jerusalem accepted them as part of the Church (Acts 8:14-25).
And finally, in Acts 10:1 - 11:18, the Lord used a vision (10:9-16), a visit from three messengers (10:17-18), and the Spirit's voice (10:19-20) to get Peter to go to the Gentiles. And when he preached the Gospel to them, he witnessed the Holy Spirit fall upon them (10:34-48). In Acts 11:1-18, Peter convinced the Apostles in Jerusalem that Gentiles were to be part of the Church, as well. The steward of the keys had done his job!