keys of the kingdom
Not the keys of the church, but of the kingdom of heaven in the sense of Matthew 13, that is, the sphere of Christian profession. A key is a badge of power or authority (cf) (Isaiah 22:22); (Revelation 3:7). The apostolic history explains and limits this trust, for it was Peter who opened the door of Christian opportunity to Israel on the day of Pentecost (Acts 2:38-42) and to Gentiles in the house of Cornelius. (Acts 10:34-46). There was no assumption by Peter of any other authority (Acts 15:7-11). In the council James, not Peter, seems to have presided; (Acts 15:19); (Galatians 2:11-15). Peter claimed no more for himself than to be an apostle by gift (1 Peter 1:1) and an elder by office (1 Peter 5:1).
The power of binding and loosing was shared (Matthew 18:18); (John 20:23) by the other disciples. That it did not involve the determination of the eternal destiny of souls is clear from (Revelation 1:18). The keys of death and the place of departed spirits are held by Christ alone.
kingdom
( See Scofield) - (Matthew 3:2).