What are the keys of the kingdom mentioned in the Bible?

In Matthew 16:19, when Jesus speaks to Peter about giving him the 'keys of the kingdom of heaven,' He is referring to the authority to proclaim the gospel message. The keys symbolize the means by which people are invited into the kingdom of God. The gospel serves as the door through which one must enter to find salvation. It emphasizes that salvation is not by human effort but is granted through God's revelation and Christ's redemptive work. Thus, the keys represent the church's mission to declare this good news and the spiritual authority given to its leaders.