The keys
Jesus gives the keys to the kingdom of heaven to Peter and the church. The kingdom of heaven is not only the eternal paradise of light, but also that particular way of living on earth that God wishes to offer us through knowledge of the Gospel and the power of the Spirit. If Jesus is handing over the keys to Peter and the church, it means that there are some doors that require those keys to access that particular way of living in happiness and well-being which God wishes for man. Those keys are in the Gospel, they are the Gospel themselves. They are the keys of knowledge. They are the new and innovative spiritual and mental procedures which, once known and learned, have the power to completely change our mental and spiritual vision of life. The task of preserving those keys and of transmitting them to the hearts of man throughout history as well as of being the gatekeepers of the transparency of God's Spirit on earth has been given to the church as a service to all of humanity.
This divine delegation is an extremely valuable, delicate service, and an enormous responsibility because it is in God's name and for the name of God's people.
There are two very poisonous temptations that the evil one can offer those who are committed to this service/task of preserving and revealing those keys to man. The first is to transform this service of inspiring humanity into a hysterical and frantic power, and it is expressed in Luke 11:46: Woe also to you scholars of the law! You impose on people burdens hard to carry, but you yourselves do not lift one finger to touch them. The second and even more terrible temptation is to create a monopoly of this knowledge and these inspiring powers in order to keep humanity enslaved in ignorance, making it easy prey of tyranny and black magic. This temptation is expressed in Matthew 23:13: Woe to you, scribes and Pharisees, you hypocrites. You lock the kingdom of heaven before human beings. You do not enter yourselves, nor do you allow entrance to those trying to enter.
Whenever this primary service becomes weighed down by these two temptations, they become a matter of prestige, vanity, power, arrogance, wealth, and bullying, and Peter and the church lose their flavour and light. They become useless and can only be trampled upon and rejected by men.