Clearly the significance of the "keys" is to make someone the Master of the Palace The "Palace" we are talking about is the Kingdom of Heaven. I really don't think Peter is the master of the Kingdom of Heaven, do you? That would be a new title. What do you suppose these keys are, exactly? Did anybody else get these keys or just Peter? Why did He give Peter these keys to the Kingdom of heaven?
I can't help it, it's what Jesus said: "I give you the keys to the Kingdom of Heaven." Once again, we have to pay particular attention to what He actually said.
In Matthew 16:19, Jesus is specifically addressing Peter. We see in the book of Acts, Peter leads in the “opening of doors” to three different groups of people so they can enter the Kingdom.
- In Acts 2, it is Peter who preaches in Jerusalem on the Day of Pentecost; about three thousand Jewish people are saved that day. Peter’s preaching had “unlocked the door” of heaven for the Jews.
- Later, in Acts 8, the Samaritans believe the gospel and receive the Holy Spirit; again, Peter (and John) was present for this event. Peter had “unlocked the door” for the Samaritans.
- Then, in Acts 10, Peter brings the gospel to a Roman centurion’s household, and they, too, receive the Holy Spirit. Peter had “unlocked the door” for the Gentiles. The “keys” that Jesus had given him worked in each case<.
When the Apostles organize the Council of Jerusalem to make an authoritative judgment concerning the Gentile question, it Peter to whom the Holy Spirit sends a special vision (the one with the large sheet being lowered to the ground.) Peter not only receives this vision individually, but interprets it correctly, and explains this to the others at the Council.
This shows that different Apostles evidently had different roles--- James, the head of the Church in Jerusalem, convened the Council and formulated its decrees; Peter, who received the actual vision from Heaven, taught it and confirmed the brethren.
So Peter was "opening a door" here. But the power of the Keys also includes the power to "shut" the door.
That happened when Pete excommunicated that major troublemaker Simon Magus.